Ask me a Question

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832 thoughts on “Ask me a Question

  1. I do not seem to be able to get the dirty marks off the windows (outside) of my car, do you have any suggestions.
    I have been told Windex window and chrome cleaner

  2. Hi Doc
    How to clean BBQ fat or grease off the patio roof without removing the colour of the patio roof it’s been there for awhile. Thanks

  3. I have a problem in my fibreglass swimming pool a black stain has appeared in areas in the swimming pool been to pool shop no one can provide a soulition to the problem it looks like black mould stain will not scrub off I can send photos if you require

        • Have you tried “shocking” the pool – adding an excess of chlorine or a persulphate salt? It’s job is to remove the chloramine smell by oxidising it through to salt and nitrogen, and it may just be what you need. ask your pool shop about “shocking” and they’ll explain it to you

  4. Hello Dr Chemical,
    I have access, through work, of empty 15L plastic tubs that held a spa sanitiser Spa Fresh.
    Hydrogen Peroxide 150g/L
    I plan on cutting the tops of to use as planters for herbs and vegies. My mate says I’m crazy and going to poison myself.
    Your thoughts.
    Steve the Spa Man

    • Nope, it’ll be fine. H2O2 is very unstable and degrades quickly in sunlight to oxygen and water. Stick them out in the sun for a few days and they’ll be right. But even if you put dirt in them the dirt will quickly neutralize it

  5. Hi Dr Chemical

    I have black porcelain wax that according to the building company still has the transportation wax on them.. They have attempted to remove the wax 3 times twice with a general purpose tile and grout cleaner and once with a product especially designed for this purpose. However there has not been much success and I am still getting footprints, wet stains and patterns in my tiles, I don’t know why I bother mopping them. When I mop it is like the tile is reflecting the water and product that I use whether it be methylated spirits or a generic tile cleaner. Are you able to give me any advise on how to fix this as at the moment I really hate my tiles.


    • Spray some oven cleaner onto it, give it a few minutes to react and then wipe it off. That should remove the last of the wax.

  6. hello I have plexiglass fan blades,what is the best way to clean and keep dust free, is Mr Sheen usable on these. Thank you

  7. Dear Dr Chemical
    I wonder if you are able to help me, I have a ink stain on a cream polyester elastain top, the ink is from a Uniball black waterproof pen. I have not tried to remove it yet, but have not had success in the past with trying to remove ink with my usual laundry products.
    Thank you

    • In order of increasing strength, metho, isopropyl alcohol, acetone. Get some acetone from a hardware store, and dip an inconspicuous part of the garment in it to test for colour fastness of the dye. If all is well, dip the ink part into the acetone in a glass – dip repeatedly and you should see the acetone take on the colour of the ink as it dissolves out of the garment

      • Thank you, I didn’t want to do anything that may have set the stain, until I heard from you.
        I’m off to the hardware store!

  8. Hi Dr Chemical

    I have a fabric wing chair that has brown Mold – what do you suggest I should I clean it with to remove stains

    Regards Marg Shields

  9. Hi Dr. Chemical
    I have terracotta tiles on a balcony which have various stains (bbq grease, marks from pots and pet stains). What do you suggest I use to remove them?

    • Mr Sheen. If that doesn’t work, try a non-caustic oven cleaner, but add the Mr Sheen afterwards, as the oven cleaner can dull the surface. Also, metho or isopropyl alcohol will wortk

      • Thanks for the tip. I did a spot test first. Non-caustic oven cleaner was too harsh so end up using rubbing alcohol which cleaned the leather well.

        But now I am left with clean but dull looking leather seats so I tried Mr Sheen but still the leather is looking a little dull?

        • Ok -get some neatsfoot oil from somewhere (not sure where) and rub that in. Alternatives are shoe polish (depending on the colour of the leather) or Dubbin. If using shoe polish or Dubbin make sure the seats are well-rubbeb afterwards for obvious reasons. Dubbin is clear so that’s the best option

  10. Hi Dr Chemical,
    Hoping you can help. We have a gloss white vinyl wrap cupboards in our kitchen which have discoloured (yellow) a great deal.
    Is there anything that could be used to bring these back to white?
    Thank you

    • Not really – it oxidises with age and that causes yellowing. But if anything will work it’s Brasso – it might rub the upper layer off and get back to white, if you’re lucky

    • White King Stain lift will get that off. Spray on, leave it for 10 min or so, then rub in and rinse out. Repeat if necessary

  11. I have about 25 spice containers that are metal with clear plastic windows. The one that contains Turmeric has etched the plastic and left it opaque with a very viscous layer on the inside. The Turmeric is the only one that has done this. What reaction is taking place and is there anything nasty in the viscous layer that means I should throw it all away?

    • Not sure what it would be, but no I wouldn’t worry about it. No doubt one of the components of the turmeric has adsorbed into the plastic. Nothing to worry about. But if you wanted to clean it, Ajax powder Cleanser would do it. But make sure you rinse it out well afterwards

      • Pardon me dropping in! Turmeric is a strong yellow dye and also contains a reasonable amount of oil, even when dried. It is light reactive, best stored in a completely opaque container.
        As it is also quiet powerful in food, we tend to use very little of it, so it stays in the container for longer times. It sounds like Marie’s container has an oily buildup from the Turmeric.
        Storage time for Turmeric shouldn’t be longer than about six months, probably shorter if exposed to light.
        I’d say probably toss it and then consider storing the new lot in an airtight tin

  12. Dr Chem, I read your advice on cleaning pavers with hydrochloric acid and thought I had bought some. However it turns out I have a new jar of Glitz caustic soda. Do you recommend this product for anything? The label says removes grease and grime. perfect for making soap”. The only directions on the container are for clearing drains, and a reference to their website about making soap.

    Thank you for all the advice you have given me.

    • Yes, it’s useful for all those things. Oven cleaners and drain cleaners use caustic soda as the active ingredient, so it’s pretty useful

  13. Hi Dr Chemical,
    My son has a large fresh engine oil stain on an unsealed concrete garage floor. Can you please advise on the best way to remove it?
    Kind regards,

  14. Thanks for your website – I have allowed bird poo to harden on the car bonnet – what is the best method to remove it without causing too much damage??

    thanks in advance


    • Well it depends a little bit on how old your car is and what type of paint it is. Assuming it’s a modern car and it’s either a baked enamel or two-pack polyurethane finish, you should be pretty right. Boil the kettle and tip it over the poo – that should get rid of most of it. Anything that’s left behind should be removed with Brasso or #2 Kitten Car Polish

    • many thanks another question what should you use to clean internal red cedar windows – have sanded but water stains remain. Have read that using a tea bag in a stocking (shannon lush) would do the trick??!!

  15. Hi Dr Chemical,
    I have recently had a Caesarstone benchtop installed, and noticed you suggest Mr Sheen as a cleaner on granite benchtops. Is the same product safe for Caesarstone?

  16. Hello, I would like to “clean” the grout around my floor tiles throughout the inside of my home. Do you have a recommended product for this task? I have tried white king in the past but with little success. Your help would be appreciated.

    • Get some oven cleaner and spray it directly on the grout. Give it a couple of minutes, then rub a stiff brush along the grout lines and it’ll come straight off. Or you can an outdoor broom with stiff bristles and a small head if you wanted to avoid getting down on your hands and knees

    • Try a non-caustic oven cleaner. Spot test on an inconspicuous section of the sofa first, but it’s very unlikely that itll cause any issues. Or metho will work as well

  17. Hi Dr Chemical,

    My cat indoor vomited on my coloured linen bedspread. I soaked it in napisan vanish (the pink one for coloured clothes) but it has only slightly faded to a yellow colour. Any suggestions?

  18. Hi Doc,

    My sons dog has left urine stains on my porous brick pavers outside in the patio. It has left stains. How do I remove the stains.

    • Try any acidic kitchen or bathroom cleaner (Ajax Spray & Wipe, Easy Off BAM Power Cleaner). If that doesn’t work, use oven cleaner or caustic soda.

  19. Hi Dr Chemical,
    My husband left a power cable with dark green enamel paint on it on our beige coloured microfibre lounge chair! Is there any way to remove the paint? Or is the only recourse to get rid of the chair ??….or perhaps the husband ?
    Many thanks,

    • Get some isopropyl alcohol from an electronics store. sit a rag on top of the paint and soak it with the IPA. Wait an hour or so and the paint should just peel away. Or try the same thing with acetone, but be careful – it’s a stronger solvent. Try it on an inconspicuous area first as it may leach the dye out of the microfibre

    • Probably the only way would be pool strength bleach (12%). The bleach you buy from the supermarket is only about 4-5% normally. Having said that, peroxide is a pretty strong oxidiser on its own, although the stuff you were usig was probably pretty dilute – the strong stuff is not available over the counter

  20. Hi Dr Chemical.
    What do you suggest on how to clean my shower drain pipes.
    whalso what chemicals to use, my wife has very long hair and
    over time i thinks it is starting to clog up
    .Many thanks Bruce

  21. Dear Dr. Can you recommend a method to ‘un-shrink’ a knitted wool garment please? It’s only ever been washed in luke warm water and wool wash.

    • Sorry – can’t be done. When wool shrinks it converts from an unnatural state (induced during processing) to its more stable natural physical form.

  22. Hi Dr Chemical, i have 2 questions
    how do I get chocolate (nutella) from a white shirt with navy stripes. the stains are courtesy of a grand child

    how do i remove orange soda stains from wool carpet.

    • I’d use White King Powerlift laundry prewash on the first one. Spray on, rub in with your fingers and rinse. Mechanism of enzymes is a little slow so it might take a few minutes. For the carpet Preen Oxy Action. Just spray on and leav it. But both products would probably work for both problems.

  23. Hi Dr Chemical
    Great show on Curtin FM. Thank you.
    You mentioned about getting muck off bricks (white stains) and said something about “wet” brick. I asked at Bunnings but they were not sure what I meant. Could you explain it again for us poor elderly people. Regards

  24. Hi Doc
    granite headstone has a lot of build up I assume from the bore water I was considering using hydrochloric acid diluted perhaps 20/1.
    would this be ok? the head stone has statues on it I think they are some sort of hard coloured plastic would acid damage them. can you suggest any other chemical?
    Oh and one more thing I have been using baby oil on the granite to keep a shine but the dust seems stick on anything you can suggest to keep the shine?
    thanks Ed

    • You can use the HCl as strong as you like – it won’t hurt the granite. But for the bore water residue I’d do it 1 part in 3. And use kitten car polish (#1) to polish the headstone

  25. Dear Dr,
    Thank you for Curtin radio segments. What product can I use to remove green, yellow & white stains off grey brick pavers? Thank you.99

    • Sprinkle caustic soda flakes, wet with a minimum of water, and scrub in with a stiff broom for 10 min or so. Let it soak for another 10 min then hose off

  26. I remove bore water deposits and shower soap scum and calcium deposits very easily by using a sponge with a scourer on one side on which I put a squirt of Jiff and then pour a little Bondall Ranex Rustbuster onto it. Just wipe it on the problem area using the scourer side and it comes up spotless.

    I use this method for a number of difficult stains also.

  27. Hi Dr Chemical.
    i have just been listening to you on Curtin radio. We have been told that the white marks on our dark bathroom tiles in the shower is phosphorous and it is virtually impossible to get off the tile and we should look at replacing the tiles. Do you have any suggestions?

  28. Hello there,
    My motorbike rear wheel has chain oil spots on its alloy rim. It’s proving hard to remove with regular bike cleaning products and a toothbrush. Would there be a specific product or alternative way to remove these spots?
    With Thanks and Best Wishes,

  29. Hi Dr Chemical,
    I love listening to you on Curtin FM! My 4yo son had one of those rubbery sticky hand things and stuck it all over the TV and wall, now there is a greasy, sticky mess that I do not know how to get rid of. I have tried microfibre cloth with a little water but just made it worse… not sure what is safe to use on the TV. Can you help?

  30. Dr Chemical, I bought some Mr Muscle oven cleaner but it dispenses in a foam which is not really ideal for applying to shower floors. After reading in one of your posts that Easy-Off has a light spray I bought some this morning. I wonder if I have the right one now. The can reads ‘Easy-Off, oven, heavy duty cleaner, no scrubbing required. super fast 5 min clean.
    Thank you.

  31. Hi
    Hoping you can assist with advise on removing a white stain above the waterline on the surface of a fibreglass pool..
    I’ve been told it’s chlorine bleaching.
    I’ve tried polish for fibreglass boats, with little result.
    Any advise would be appreciated

    Regards Colin…

      • Hi, I’ve tried Ajax, jiff, car and fibreglass boat polish, with no result.
        I’ve been told by my pool supplier its bleaching caused by chlorine gas..

        Any suggestions greatly appreciated

        • Hmm. The problem with that theory is that the oxidising effect of the chlorine in the water is much stronger than any gas that’s coming off the water. All I can suggest is that it’s some synergistic effect caused by the gases coming off the water (mostly chloramines) and the UV oxidising effect of the sunlight.

  32. Hi Dr Chemical
    One of those liquid filled freezer blocks was left on a small round lacquered copper table top and it has leaked removing the lacquer in a rectangular shape where the block was sitting. Can you please advise the best way of cleaning the copper. It has a pattern engraved on it.
    Thank you

    • Thanks for the link. Too much to go through quickly, so I’ll do a post on the whole article when I get a chance. But when she says “what we call glass cancer” she means “what I call glass cancer.” Glass is an inorganic material and so it cannot get cancer. What it does get is a buildup of insoluble (sulphate) salts that are not easily removed. Rubbing an oil of some sort over it may well work to create a wet look, but I’d be going to Bunnings and getting a “wet look” brick sealer from the paint section. These products are designed to cover up efflorescence on bricks and they work pretty well. Just paint a little on and let it dry and see how it goes.

      But another approach comes from a comment on my blog. He took to a shower screen with a razor blade and said that it got 95% of the stuff off. Might be a bit of work, but probably worth a go.

      • Thanks for getting back to me, much appreciated, I look forward to your post. I actually found your info on shower screens, after posting; I purchased some “Bar Keepers Friend” from Coles this morning – right next to the Brasso, as you mentioned, and on special! Will try the blade too.

        Thanks again.

  33. Hi, I’m house sitting for a relative who has a black glass induction stove top. It has a few minor light scratches but a white mark has appeared that I can’t tell if it is a scratch or not as it feels smooth but it won’t come off. I don’t want to use any harsh cleansers or scourer as it will scratch but I want to remove it before they get back. The mark is slightly curved which makes me think it may have something to do with the pot.

  34. Hello Dr Chemical,

    Can you suggest a product to remove perspiration smells from shirts? I wash my clothes in warm water and while they appear to be clean, once I start to sweat the original perspiration stain is reactivated.

    • Warm water with a premium brand detergent will remove body odour smells. They are probably the easiest things to remove. So they can’t be “reactivated”

  35. I’ve heard that magazines and books should not be wrapped in plastic if you wish to preserve them for long periods (ie many years) as it promotes decay. Assuming your not wrapping with absolute air tightness on a humid day, and so not trapping moisture, is this true? At first I thought mold might be the problem, but perhaps there is some other chemistry involved with cellulose and plastic wrap when contained in a near airtight environment for long periods going on.

    • Oven cleaner for the grime and Ajax Spray and Wipe (with lactic acid) for the minerals. If it doesn’t work you can use hydrochloric acid (1 part in 4)

  36. I have just my carpets cleaned and my granddaughter hd a blood nose and drilled on carpet. Also done on bed sheets

    Googling gives me mixed results
    Please help before I do something wrong. I know I should know this.

  37. Hello Dr Chemical,

    Would you help me find out if the window tint ( I think that is what it is ) that is flaking off the inside of my office windows is toxic? The small flakes cover a good portion of the room, the look like dust on the surfaces they cover, and float like dust.

    Anthony ‘I want to wear a mask to work’

  38. Hi,
    I have just had a new man made stone (quartz based) bench top installed and wondered what the best cleaning product is for it. In my reading on the topic I see that users are advised not to use sprays such as Orange Power as they may damage the surface. Also I have noticed a few “flat/dull” areas on it that I didn’t see at the time of installation. The tiler didn’t cover the benches while he worked and there were splashes of tile cement on it before he cleaned up. Could this have caused the flat spots? How can I restore the shine?

      • Thank you. I’ll be washing a hand knit cardigan by hand. I’ve been using that Biozet for general laundry. Did you know that there is a new one called Biozet Attack Rapid? The directions are that one can shorten the washing time, wash in cold water and use less product. Are you familiar with that one?
        I have been buying both at Woolworth’s when they are on special for about half price, because as you mentioned in a previous post it is quite expensive.

          • The original (liquid and powder) and the new Rapid were on special at Woolworth’s Lane Cove (Sydney) a couple of days ago.
            Product Review gives mixed reviews. I’ll be interested to hear your view if you get to try it.

            Oh, one more thing if I may. Do you endorse using white vinegar in the rinse cycle occasionally, also as rinse aid in the dishwasher?

          • I’ve been unable to get any info on the “Rapid” version of BioZet, but it appears to simply be a “double” enzyme formula – presumably just higher conc. I wouldn’t take much notice of the Product Review, particularly as more than any other laundry product, this is a temperature dependant product. At 40 degrees the results are spectacular, but they drop away very quickly at higher or lower temps. As a rinse aid vinegar in the dishwasher can help removinfg mineral deposits, but it won’t work as well as the off-the-shelf products. In the laundry it can have a pH neutralising effect for highly alkaline detg that can have a softening effect

  39. Hi
    The carpet in my son’s room got wet in one of the recent storms .
    We vacuumed the spot and covered it in Bicarbonate soda but the strong mildew smell is still there. How can we remove the mildew?

    • No simple answer for that I’m afraid. Only answer is lots of air. I had exactly the same problem in the old house I’m living in. Several weeks of leaving the window open has pretty much removed the smelll. But one thing you can do is get an off cut of some pine from Bunnings and stick it in the corner. Pine has a beautiful natural smell that will help to mask the smell

  40. We have red mahogany floors sealed with tung oil followed with a Peerless product called Gemini finish (GEMINI SATIN is an Acrylic polymer water based floor polish designed to provide a durable satin/low gloss.) There are white scuff marks in some areas where chairs and shoes have been dragged along the floor. How do I remove these marks and/or the Gemini finish? (It appears that the Gemini finish in those areas has been permanently damaged, so I’d like to remove the Gemini finish).
    Many thanks.

    • Some floor polishes are designed to be removed with ammonia. Try mopping with a a cup of ammonia in a bucket of water and see how you go. Alternatively, washing soda. Sprinkle it around, wet it it with water and mop it in. When you’ve finished you’ll have a white residue, but it can be easily removed by mopping a second time with vinegar

  41. I have artists linseed oil on a light brown pure wool carpet. The stain is five years old and isn’t too bad but I wonder if you have any ideas about how to remove it. Thank you

    • I’d try an oven cleaner on that – use a non-caustic one. Spray it on, wait a minute or so, then wipe off. But try it on aninconspicuous area of the carpet first to make sure it doesn’t damage the carpet. It’s highly unlikely, buyt check anyway

  42. Hello, I used a chrome rim polish 10 days ago on my chrome rim and didn’t remove the polish off of one rim completely. Now it looks like a smear that the polish won’t fix. What can I do to remove the polish residue from my chrome rim?

  43. G’day DC,
    Is there a way to remove wax from wood? I have bought anti-slip drum sticks which are effectively drum sticks with the ends dipped in wax. The wax, which is red, is marking my drum kit badly. I tried a potato peeler but scrapping the wood as well.
    With Thanks and Best Wishes,

  44. A biro leaked all its ink down the front of our stainless steel refrigerator. I’ve tried a few things but without success. There is a large amount of ink.

  45. Just got new asphalt on my driveway and noticed when it dried, there were several large round white spots. Tried washing them off, but to no avail. Don’t know what they are or how to remove them. Advise please.

    • Not sure what they’d be, but you will find that they will dissipate with time. If you wanted to remove it quicker, try Kenco (from Bunnings), but personally I’d just leave it

  46. Hi Dr Chemical, I washed a red fleece cardigan in a slightly warm hand wash and left to soak overnight as I had used a spray to get a small oil spot out. On rinsing there were small black marks on the top where the two side of the stud buttons were lying against fabric all the way down the top on both sides. I am presuming the fasteners are brass. What are the black marks and how can I get them out of my very good red top.

    • If it’s from the brass you should be able to get it out with the sulfamic acid in Easy Off bathroom cleaner. I forget the actual name of the product but look for sulfamic acid in the active ingredients on the label

  47. I’ve got a white top which is 73% nylon, 27% lycra elastane, which has been discoloured quite yellow (went through the wash with a yellow item).

    What’s the best way to re-whiten a garment like this please?

    • There is no simple way to do this, but if you use a premium brand washing powder with a 40 degree wash it will wash out eventually.

  48. Hi Doctor,
    I recently asked a question on Curtin radio regarding the cleaning of castor oil residue from a vintage aircraft we operate at Serpentine Airfield. The linen fabric surfaces are coated with Butyrate dope, so I am reluctant to use harsh caustic cleaners.
    You suggested an alternative, but regretfully I did not take notes. The castor oil is an insidious material to clean, to date we use hot soapy water, but this is not great.
    Many thanks

  49. In my home I have jarrah floorboards. What’s the best way to clean them? Yesterday I was at the Perth Home Show and I asked a flooring salesman and he said to use odorless turpentine and water, but a flooring website said that this would be harmful to the wood. It recommended “some warm water with a little mild, neutral PH detergent “. Would you agree with this? And if so – how can I tell if a detergent is PH neutral? A brand name would be helpful…. I just want to keep my floors shiny and in good condition.

    • The turps suggestion is a little odd as it doesn’t mix with water. But for a neutral pH you’re looking for the phrase “non-soap” on the label somewhere. The only brand used to be Dove, but now there are quite a few brands. Or you get one of the Long Life branded products from Bunninghs – they’re pretty good

    • Any of the ammonia based floor cleaners work – Bunnings sell a brand called Long Life that works well, or you can just use ammonia – half a cup to a bucket. After you;ve finished mopping any residual ammonia will evaporate

    • It depends what you mean by neutralise. If you mean you want to stop the foaming the best way to do it is metho. Comprised mostly of ethanol, it does a very good job of disrupting the molecular structure at the interface of the bubbles. Get a 20L drum from the hardware store and dump in as much as you need. And of course there’s no reason you can’t swim in the poll with metho in there. Also, since detergents are all biodegradable these days anyway, it will degrade pretty quickly.

  50. Is there a way to stain proof a new, white granite bench top?

    If it does stain what is the best way to remove stains?

    Thank you.

    • Try soaking it with acetone – tip some on a rag and hold the rag against it somehow for at least 10 minutes. Alternatively, try a steam cleaner with a jet type nozzle to blast the area. It should peel off

      • Use a hair-dryer to melt the glue and scratch it off gently with something. I have just used my fingernail for small areas in the past. I got a black glue backing from a hook off a painted wall this way and there was no damage to the paint.

        • Yep – that’s a good plan, as long as you’re careful not to scratch the paint. You can try rolling your finger over the top of it as well, so it all kind of rolls up. Then use one of the solvents to get the last little bits off

  51. Could you pls advise how I might remove yellow stain colour of turmeric (cat vomited dry cat food) from nylon plush carpet; I assume it’s some sort of food dye? Unfortunately stain has dried. Tried Pullman carpet spot/stain remover which usually works really well if used immediately after the ‘event’, but this time stain remains.

    • Try White King Stainlift – if that doesn’t work try Preen Vanish OxyAction. Or use Biozet Attack liquid as a spot cleaner

  52. Hi,
    Could you please help.
    I need a solution to clean greasy inside oven panels (top, bottom & sides) as well as the inside glass section.
    As I find it difficult to put a lot of strength behind the scrubbing i wondered if there was something I could spray or wipe over the grease and after some time just wipe it off.

    It would be a great help if you could assist
    Thank you.

    • Use any oven cleaner – I like Easy Off as it sprays a fine mist. Spray on, leave for at least 10 minutes and wipe. Rpt as need be for heavy coatings. The caustic ones work better than the noncaustic ones but have stronger fumes (but they’re not toxic)

  53. Hi Dr Chemical,
    I have a courtyard and I cannot seem to remove the brown sap stains left by monsteria deliciousa cuttings on limestone pavers. I have tried a range of natural and pavement cleaning products to no avail. I am trying to remove the old stains. What do you suggest?

    • Sprinkle caustic soda flakes on the stains, wet wet a minimum of water and let them soak for half an hour. Then scrub with a stiff broom and hose – if that doesn’t remove it nothing will

  54. Hey, Dr C,
    I have outside limestone flooring that has gone really green, can you advise any product or solution I can use to remove it and restore it back to its original state please

    • Nope – plants are growing on it because the carbonate in the limestone is a better source of carbon for photosynthesis than CO2. High pressure water will take some off, but it’ll grow back.

  55. Not sure if you are familiar with pindan? Red dust from aussie desert sands. Red iron ore dust essentially ( rust dust ) . Do you know how to remove from car paintwork, and rubber and plastic interiors ?

    • Yep – hydrochloric acid. Unfortunately it’ll also dissolve the car….
      No easy answer other than lots of soap and wax and sponges I’m afraid

    • I’d use an oven cleaner on the egg stain. Asfor thge paint I don’t like your chances. Try sitting an acetone-soaked rag on top of it and see if it comes off

  56. Yellow pigment leached from embroidery thread into the surrounding white cross stitch canvas when I dampened it to remove general grubbiness from handling. I would appreciate any ideas on how to remove this pigmentation.

    • I suspect it’s a dye, not a pigment. You would probably find that it will fade pretty quickly on its own anyway. But to remove it now, I’d hit it with an oxidiser – get some Preen Oxy Action, spray it on and leave it. It should do the job. Alternatively, you will find that it should wash out pretty easily if it’s water soluble enough to have smeared so easily just because you wet it. I’m not sure what item it’s in, but if it’s something that you would put in the wash that will probably do the job

  57. Hi how do you remove ground in dirt stains from coloured hand towels that have been washed,but still show dirt.Thankyou

  58. Hello, I power-washed my house with bleach and didn’t rinse the windows well enough so there is a haze on them now. What can I use to get rid of this bleach haze?

    Thank you!

  59. hi dr chemical
    How to prepare a water sample for photometry?

    The purpose of measuring N P K Ca Mg S is to determine the amount of material consumed by different types of plants in different periods.
    The initial solution, which is prepared as a nutritious solution, includes highly accurate and measured doses of substances such as
    Potassium Nitrate, Magnesium Sulphate, Climer Nitrate, Potassium Monophosphate, Ammonium Nitrate, and other materials that supply the micro-nutrients required by the plants.
    The resulting solution is very clear and after two to three days of water treatment, the water dissolved in the water (drainage water) can easily be measured by photometer.
    The problem occurs when the initial solution of humic acid and fulvic acid is added. In this case, the water released is very dark and it is not possible to use this water in photometry.
    I have searched a lot, but the easiest way is to use photometer and chemical reagents to measure the concentration of the material.
    Due to the fact that the error of 10-15% is acceptable in test conditions, it is thought to isolate humic and fulvic acids to clear water without changing the concentration of other materials.

    • Yes you’d have to filter the solution. Many spectrophotometers are available with colorimetric methods to allow nutrients and other species to be measured. The most versatile are the HACH Instruments, and beleive it or not you can get 2nd hand unit on EBay for typically less than $1000

  60. Hi Dr Chemical
    Have moved into a house with a brick surround a fire place. The bricks have been varnished or painted with some type of gloss. How can the gloss be removed?

    Many thanks

    • If anything will get it off, it’ll be acetone, but I don’t like your chances. If that doesn’t do it, try to find a product with NMP (N-Methylpyrrolidone) as the active ingredient. Not sure where you’d find one though

  61. Hi Dr Chemical,

    Can you please help me to clean the mould/dirt/scum build up around the rubber seal of my front loader washing machine? Many thanks in advance :)

    • It’s just a mechanical polish – it rubs it off. Brass is pretty soft, so it works well. But Brasso will probably work better (although I haven’t tried Autosol)

  62. Hello Dr Chemical

    A mix of bicarbonate and vinegar has stained an oiled wood kitchen bench, resulting in dark patches where the mix has sat on the bench overnight.
    Is there any way of reversing this?

    • Hmm. Tricky. Problem is I’m not sure what is causing the dark colour – the bicarb or vinegar. I’d try to steam it out. Put a washer on top, and then sit a steam iron on top and blast it through the washer. With a bit of luck the steam will desorb the dark colour and it will wick up into the washer. Or ring Shannon Lush on 6PR – as she is a furniture restorer she might actually be able to come up with a sensible answer

  63. What is the difference between caustic and non-caustic oven cleaners? What are the considerations in choosing which one to use.

    • Caustic ones use sodium hydroxide as the active ingredient whereas non-caustic ones use amine salts, as water-based degreasers do. The only difference is that the caustic ones produce sometimes unpleasant fumes (although they are not toxic). In my experience the non-caustic ones work as well as the caustic ones

        • alkaline salts are amine salts, these days used in water-based degreasers. The term caustic refers to either NaOH (caustic soda) or caustic potash (KOH)

          • Thanks for your patience. I bought an Ozkleen “Oven Power Kit” that said alkaline salts on the label. But the company’s webpage for the product

            has a link to an MSDS (in bold red writing near the product description), that lists potassium hydroxide as an ingredient. The Wikipedia page for alkaline salts lists alkali metal hydroxides, that includes potassium hydroxide right?
            I am very confused.

          • It’s kind of a semantic question, but technically Wikipedia is wrong as the definition of a salt is “the product of an acid-base reaction.” KOH is alkaline (very alkaline) but technically it’s not a salt

    • put some washing soda in there, fill it with water and bring it to the boil. Let it cool and then tip it out. The burnt stuff should wipe out fairly easily with a scourer

  64. Hello,

    What would be best for dissolving hard buildup in the bottom of a toilet bowl? HCl? How much would you think?


    • What do you think the scale would be? It looks for all the world like someone dropped grout or something in the bottom of the toilet, but I’ve only seen it in toilets regularly used by men, so I’m wondering whether it’s something precipitating out of male urine, but I don’t know enough biochem to know whether that’s possible!

    • Depends what it is – if it’s alkaline salts, HCl will do it. Get a 1L bottle and tip it all in. It won’t damage the toilet

  65. We have bought a property with a large lounge window with very bad white stains. The previous tenants had a pool outside the window and chlorine was regularly splashed on the glass. Any ideas for removing the stains (or etching)?

  66. Hi, what would you recommend for removing a really pungent smoke smell that is throughout our entire house? Its was caused from a cooking accident involving chickpeas and water left to burn to a crisp. The entire house was filled with thick smoke. (we were out) We are day 2 and nothing much has changed. Being ultra sensitive to most chemicals, (causes headaches and lung irritation) I have used bi carb on carpet couches mats and vacuumed, washed floors and some walls with vinegar. Left coffee grounds around to absorb. Spayed eucalyptus but I realize this is just mostly masking. What else to do and how long might this last? Thanks, Michelle

    • I’m afraid that due to the size of the problem there is no simple solution. For localised areas bicarb is a good option, but the only other option is air, air and more area. I have an evap air conditoioner in my house with an exhaust facility – it sucks air in through the A/C vents and expels it out the top. If you don’t have that available to you, all you can do is open as many doors and windows as often as you can for as long as you can

  67. HI

    Love your show on Curtin FM

    I am sure I heard you talk about cleaning limestone walls – but didnt catch the solution to it. We have beautiful limestone walls by the pool but the top row has gone all black and is getting very mouldy?
    Suggestions to clean before we have it sealed

    • Nothing you can do I’m afraid – if you soak it with caustic soda and blast it with a high pressure cleaner it will improve somewhat, but it will just go black again. Sealing compounds are available, but I don’t know how well they work – it’s a very porous material

  68. G’day,
    Got power steering fluid leaked over my brick paved driveway?
    Been there for a couple of months.
    Thanks man.

  69. Hi Dr Chemical…..
    I have a yellow stain underneath the toilet seat. I have tried several household cleaners including Domestos without any luck. This is a situation I have never encountered before can you help please.

    • If you’re referring to the yellowing of the plastic then Im afraid there’s nothing you can do about it. It happens to some plastics with age (HDPE I think)

  70. Hello

    For a while now I have been following Shannon Lush’s advice and substituting my Cold Power powder with BiCarb (2 Tblspn Bi carb and 1/8th = 1 Tblspn coldpower) and have been noticing that the clothes really aren’t getting clean. But being a silly stubborn thing I kept it up. I rinse in Vinegar and add a few drops of essential oil in the hope that clothes will smell nice. Really my laundry regime is not working for me and I wish I had read your blogs about 2 years ago!!
    I also wash in cold water.
    What do you think of the above? Could you recommend a cold water detergent – I have 3 boys that get very muddy and messy!! Should I wash in 30 degree water?
    Also about making clothes smell nice and using fabric softener… any word of advice?
    Btw – I just brought ‘lectric washing soda’ from the big 2 – a 40 cent price difference!! and Im going to use it instead of bicarb for everything from now on!!!!

    Thank you!
    PS will you email me the answer or do I look up here….

    • The optimum temp for washing clothes is 40 deg, as this is the temperature at which enzymes are the most active. If you used a premium branded product such as OMO or Biozet this would yield the best results.
      If there is some reason you have to wash in cold water, however, it’s hard to go past cold power, as their claim of “best results in cold water” has never been challenged by one of the other brands, which they most certainly would have done if they could.
      But you might want to try Fab – it’s the only “softergent” on the market – that is, it has built-in fabric softeners

      • Thank you!! I can also say that the washing soda does wonders!! I have gotten stains and sticky marks (from sticky tape) off the wall with it as well as using it as a detergent booster in washing machine and my clothes are now fabulously clean – even in cold water! I just mix it up with hot water first then add it.

        Any final word on using vinegar as a fabric softener?
        Thanks again!!

        • Yes apparently it does work as a fabric softener – it has the same effect as a conditioner does after washing your hair – it neutralizes the highly alkaline pH

    • Oven cleaner should do it. Spray on, wait a few minutes and it should just wipe off. If it doesn’t, try metho on a rag.

  71. Hi there,
    we have outdoor canvas awnings that are heavily stained with what looks like mould. We have tried everything it seems but it does not budge. Please help!!!

    • Sorry – once it reaches that stage there is nothing that I know of that will dislodge it. I have the same problem on a pair of pants…

  72. Hello, I have laminate kitchen top, I can see a mark on it, not directly but certainly from distance, tried to clean but doesn’t comes off, my partner said may be I have kept some hot thing/pot that has eaten away the upper layer leaving a mark on it, is it possible to any ways get rid of the mark on laminate.

    • Laminate is pretty easily stained – it’s a pretty awful choice of benchtop. If Ajax Spray and Wipe doesn’t shift it, it’s probably permanent

  73. After I had the interior of my house painted I find that the doors go dull no sheen. What can I use the take the scum or dullness off. It was taubmans paint over delux if that helps. Hope you can help.

    • Sorry can’t answer that one. I’d go to the paint counter at Bunnings (or wherever you bought it from) and ask them. Bunnings have quite a lot of ex-tradies working for them

  74. Muriatic acid spilled on to my passenger car seat??? please
    Help how do I safely clean this up??


    • I’m afraid you can’t. Whatever damage has been done is irreversible. Any residual acid can be neutralised with bicarb soda or washing soda. If you don’t have either of these handy, any washing powder will do

  75. Hi There
    My youngest son decided to change the oil on his bike, now I have oil stains on my brick paying what do you suggest I should do?
    Please advise.
    Kind Regards

  76. hi, how do i clean clear perspex that has gone yellowish from the sun. I would like it to be clear perspex again


    • Best results will be seen with Brasso Rub the area until you feel the coarse feeling be replaced by a smooth feeling. It will not fully restore it but it will improve

  77. Hi Doc, I recently purchased a pile of magnesium bulk products from Blants.
    One of these was washing soda which their website suggests can be used to remove stains and moss from concrete paths or walls in “a strong solution”.
    Can’t seem to find out what a strong solution is per litre of water, or an 8 litre bucket. Any suggestions?

    • Washing soda isn;t that strong. Use caustic soda. Spronkle flakes on area, moisten with a minimum of water (mist setting on hose) and use a stiff broom to rub it in for about 10 min. Then hose off

  78. hi there I have a problem with a white oxide leaching out heavily around aluminium pool posts set in concrete with tiles on. After heavy rain the problem is much worse and it dries to a 2mm thick white substance I had it tested and it came back 60% Al203,Ba0,Ca0,Cr203 ,Fe203,K20,Mg0,Mn0,Na20,P205,Si02,would you have any idea of the cause or how to stop this leaching? Thanks

    • Here’s what I think is happening.
      Aluminium will react (dissolve) when exposed to highly alkaline material, like cement:

      2 Al + 2 NaOH + 2 H2O ? 2 NaAlO2 + 3 H

      In other words, if you embed aluminium in cement, you’re asking for trouble, and this is exactly what will happen. Whoever built the structure gave, or was given, very bad advice. Stainles steel should have been used.

      In other words, I hate to have to tell you there isn’t anything you can do about it…

  79. Dear Dr,

    You finish your article on CO2 (August 6, 2012) by writing “So how could a gas present in such miniscule concentrations be influencing our climate?

    That’s what I’d like to know. Tomorrow we’ll look at why people say it does, and whether these explanations hold up.”

    This sounds very interesting, but I cannot find the follow-up article…

    • I’d forgotten about that – I’ve been asked by several people to do a series on Climate Change. I’ll get onto it

  80. G’day DC. We have a developing pale brown/greyish water stain mark on our enamel bath and sink. It is around the plug hole of the sink and floor of bath. Oven Cleaner?
    With Thanks and Best Wishes,

  81. Greetings Dr Chem.
    I was reading about Rain-X on Product Review. If you know of this product, would you suggest that Mr Sheen would get the same result on windscreens, without some of the negative results reported by some folk?
    Thank you.

    • Mr Sheen and Rain X almost certainly use the same active ingredient – a silicon emulsion. I’m not aware of any negative results from Mr Sheen

  82. Hi Dr Chemical,

    I put a thick layer of newspaper outside on some stone tiles today and then placed some oven racks on them. I then sprayed the oven racks with Easy Off Bam oven cleaner and when I went to check on them about 20 minutes later the stone tiles underneath the newspaper had 3 large dark stains on them.

    Could you please advise if there’s anything I can use to remove the stains?

    Many thanks,


    • As it is a natural stain, I would be trying in enzyme based cleaner on that. Get some white king stainlift laundry pre-wash and spray some on and leave it. After a little while you should see the stain dissipate

  83. I have tried to find any historic answers to my question on your web site but to no success.
    My question is what product can be used to clean stainless steel cooking pots and BBQ plates of the dark stains that accumulate over time.

    I have tried “jif” and steel wool. However, after a lot of scrubbing the result is not a total success. To further explain what I am trying to remove is the black stain on a Weber grill after cooking roasts on the grill.

    Thank you,


    • Firstly, use any oven cleaner. Spray on, leave for a few minutes, then rub off with a scourer. Then to polish the stainless steel, use Brasso. It is the best metal polish for any surface

  84. How do I remove the glue that keeps a label stuck on a glass jar. For example, the Vegemite label. Some of the adhesives are really sticky and are difficult to remove.

      • Thanks Doc – and knowing that you favour acetone as a remover, I had already tried using acetone, but it didnt work. I used the Coles Nail polish remover (ingredients: Acetone, water, alcohol denat, C12-15 Alkyl Benzoate, Cetyl acetate, Stearyl acetate, oleyl acetate, ethyl acetate, acetylated lanolin alcohol, benzophenone 3, citric acid, fragrance, hydrolyzed elastin, tocopheryl acetate, and Yellow 11 (CL47000).

        Using this product the glue was softened and it just swished around the surface of the jar but wasnt actually removed. Is the Coles product not good enough? What product do you recommend?

  85. Hi There, Car dealership with light grey polished porcelain tiles. Cannot remove the tyre marks after the vehicle has sat on the same spot for a few weeks. Size of each mark is the size of the tyre area touching the tiles. However if the vehicles are driven around over the tiles, they don’t mark, only while they are standing still over a period of time. What do you suggest? Thank you

    • Metho on a rag should do it. If it doesn’t, get an oven cleaner (like easy off) And spray it on the black mark. White to all three minutes and then you should just wipe off

  86. Hello there, my friend has very small spots of cannabis resin stuck on his kitchen ceramic floor tiles. Any advice on how to remove please?

    • Acetone. Put some in a cup, isolate the part of the shirt with the ink and then repeatedly dip it into the acetone.

  87. Hi Dr Chemical, l have white vinyl wrap kitchen cupboards which have yellowed. I would like be rid of the yellow hue. I notice the original colour where the stainless steel handles are secured to the cupboard. Thanks for your advice.

    • Unfortunately that is oxidation of the vinyl with age. If anything will rub off the oxidised layer it’s Brasso

  88. Removing oil stains from concrete.( 6 months old at least).
    1 method I heard of was using plaster of Paris and dishwashing liquid!!!!!?
    It is a standard concrete hard stand although the driveway has some too but it is red asphalt.
    Having previously worked in the bitumen industry, I am aware of what petroleum based products do to bitumen.
    Will I need 2 different methods?

    • The Plaster method is a Shannon Lush method. Like everything else she says I doubt it’d work. Best oil remover is caustic soda. Sprinkle flakes on, wet with a minimum of water and rub in with a stiff broom – then hose off. Alternatively, Bunnings sell a product called Kenco that works well

  89. I have caustic pencil stains on my white vanity unit in the bathroom how can I remove the stains thankyou

  90. Hi Dr Chemical,
    We have just moved in to a new house that has carpets and would like to know if there is anything we can put on the carpets to deter one of our dogs peeing. Our previous house did not have any carpet and she always went outside. Now she seems confused.

    • Try vinegar. They will smell a bit of course, but since dogs work off smell that’s inevitable. An alternative approach I have heard of is leave a couple of jars of Vicks Vaporub with their lids off in the area

  91. Hi Dr Chemical
    I,ve been trying to get rid of tiny red ants in the pavement floors in the driveway, but it keep coming back. what can I use to get rid of them? Not able to find the nest as it is not coming from the lawn. Please help. Thank you.

  92. Hi Dr Chemical,
    On Tuesday 20 June I was listening to Curtin Radio and a lady asked you how to remove a stain from her toilet. Could you let me know what you advised her to use please. On the same day you talked about Enviroshield and Rainx
    Kind regards

  93. Have light coloured leather furniture that needs a good clean, bit grimy, need something to power off the dirt. Regards barry.

  94. Hello Doc. I re-read your 2012 advice on Dynamo being the preferred detergent for washing clothes. Is this still your recommended product?
    I prefer using a liquid to powder, as I don’t want to mess about dissolving the powder before adding to the wash.
    I like your idea of tossing the bottle cap in with the wash (remembering to place the opened container far away so I don’t knock it over and create more mess).

    Thanks for a great website. Have passed it on to several friends who love it too.
    My one gripe is that I have difficulty in tearing myself away from it to do some of the boring staff, like laundry. Might have to go out for a soy latte instead.

    • Dynamo is pretty good, but the best liquid is now BioZet Attack, as it uses enzymes. But it’s more expensive….

  95. I was listening to Curtin the other day and you were saying something about coating the shower screen with (I think enviro clean) which after cleaning the shower glass and tiles it puts a coating on to stop further build up of calcium stains. Can you let me know if the name is correct because I can’t find it anywhere
    Regards vicki

  96. We have a high gloss black T.V cabinet,which has small fine scratches on it,suspecting from microfibre cloths which have been used to clean cabinet in the past.What would you suggest to get rid of marks. TIA.Pauline

  97. Hi Dr Chemical
    There is a horrible smell coming out from the kitchen sink hole. I’ve tried lots of ways of getting rid of the smell but it is still smelling every now and then. Is there some chemical that I can use to pour into the drain hole? Thank you.

    • Yep. Get a 2kg tub of caustic soda from bunnings. Tip half of it into the sink, using a minumum of water to rinse the flakes down the plughole. Leave it for half an hour while you have a cup of tea. When you come back just flush the sink with copious water to flush the caustic through and that should fix the problem

  98. Hi,

    Can you help me with removing BBQ/Fat stains form unsealed new Merbau timber? really would like to remove the stains before sealing..

    Also do you have any advise for Cat Urine accidents into carpet?

    Many Thanks.

    • Get some washing soda, make it into a paste and scrub the timber with a scourer. But try it on an inconspicuous bit first. The danger is that white powder (the washing soda) will impregnate the timber and be visible when it dries. Or yoy could try an oven cleaner, but once again try it on an inconspicuous area first

    • Sorry don’t have any magic formulas for that – the problem is that any water based product will leave water marks. I’d try Isopropyl Alcohol (from an electronics shop) on an inconspicuous area to see if it leaves marks when it dries.

  99. My beautiful new Scanpan has been getting a workout and is now starting to look like its older cousin with stains that wont come off in the sink. How do I remove the black from the pan exterior and to keep it looking clean on the inside?

  100. hi i have stains on carpet from spilt beer that has dried brown. i cleaned with a damp cloth and mild soap, no luck so far, what can i do now?

  101. We have had our black leather couch in storage (shipping container) while we built our house. When we recently took it out we found mould all over it. It wipes off but I suspect it will come back again with time. Any suggestions how to rid the mould for good?

  102. Hi Dr Chemical,
    What can I use to remove weeds from in between my pool pavers that is non toxic to animals?. The pavers have sand between them and constantly have weeds or algae growing

    Also, is Mr Shen ok to clean leather lounges as well as leather car seats?


  103. Hello, I’m about to buy a used car from a dealer and the car stinks of tobacco smoke.
    Is there a sure fire method of removing the smell permanently.
    The dealer assures me that they can do it by using some sort of odor bomb, I’m very sceptical and have told them I won’t buy the car if the smell remains.
    I would appreciate any solution you could offer.
    Regards Greg.

    • Air-O-Zone used to make a tobacco smell neutraliser that worked quite well, but it’s not on the market anymore. There’s no short term solution that I know of. But if you park the car somewhere where you can leave the doors open for a few days that should diminish it somewhat. Alternatively, go to Bunnings and get a pine offcut from their cut shop and stick that under your seat. Best air freshener going around, and might mnask the tobacco

  104. how to remove slippery moss from old pavers? Old houses here are very close together and path is 1 metre wide and no sun in winter. I do not want to use water pressure solution as I know it goes under next door house and she has mould problems inside so don’t need more water around. Any ideas as I must do something soon or I’ll break my leg!

    • If you don’t want to use water then I’m afraid you’re out of options. Perhaps sprinkle some sand onto it to assist with grip

  105. I have 20 year old stainmaster carpet- the one Pro Hart threw food onto in an old commercial. In the past I have been able to remove absolutely any stain (until now). I
    spilled a mug of black tea on the carpet. I mopped up as much as I could with paper towels and used my go to product Scotchguard spot stain remover. I t helped a bit but not much. I then used used Shannon Lush solution -glycerine applied with a cotton ball, leave 5 mins then damp sponge the stain with white vinegar and sprinkle with bicarb. I still have the stain. Can you help please.

    • Try some enzymes. Squirt some White King Stainlift prewash and leave it. Few applications should remove it. If that doesn’t work, try the same thing with Preen Oxy-Action

  106. Hi.
    I bought a leather couch that has been smoke damaged, the smell is in the leather and the fabric section underneath cushions, at the moment I am trying equal parts vinegar and water, can you suggest anything else?
    regards Anna

  107. Dear Dr Chemical,

    I recently had my wall rendered. Some of the render has ended up on my brick paving. How do I remove the render marks please.

    • Try a heat gun. It will probably just flake off. If not, Get some hydrochloric acid from the hardware store and use at 50%

  108. Hello My seats out on the patio have faded due to the sun .I would say that the viynal seats have been sunburnt on the back of the chairs the rest of the seats are ok Just the part which receives direct sunlight These seats are a very common type If I was going to desscibe them they are the type which comes with the glass tables Hope this helps

  109. Hi Dr Chemical
    I have a leather jacket with quilted padded lining & knitted collar, cuffs & waistband.
    The back is also a type of knitted material – not sure if it’s wool or acrylic.
    The leather is is good condition , however the knitted section needs a good clean.
    Should I dry-clean or do you have a simple, inexpensive method?

    • Pick an inconspicuous spot and spray some non-caustic oven cleaner. Wait about a minute then blot it up with a wet washer. If it’s just general grime the oven cleaner should do it and it won’t damage the material. If it works then you can use it on the rest of the jacket.

  110. Hi Dr Chemical, can you help me understand climate change, l guess you are skeptical , my take on your previous articles . You are a man of science , yet seem to differ from prevailing science opinion. I be reading your position incorrectly, however , can you expand on this subject so the non science person can understand… thanks Andrew

    • Good question. The issue is muddied somewhat by the fact that it is now no longer a scientific issue alone. Politics and money are now involved. I intend writing a series of articles on this at some stage that lay the issues out so that a non-scientific person can understand them.

  111. What are the effects on the human body if 120 ML of sunlight liquid dish soap is mixed with 350 ML of Crown Royal whiskey and 200 ML of coca cola. Then the combined mixture is completely ingested over a period of 3 hours?

    What sumptoms would this have on the human body?

    • What an odd question. Try a poisons information centre, but the soap would probably make you sick. There’d be no lasting effect that I could see

    • Isopropyl alcohol (electronics shop) or acetone. Try the IPA first – acetone is more aggressive and will strip oils out of the leather (but can be reoiled later)

  112. Hi Dr , I am desperate to be able to clean a laminate bench top. An oven tray (aluminium) was left on the bench and water seeped under it and sat for a long time. Now I have a large rust stain. That is it’s a stain but also raised. I didn’t want to use an abrasive in case it wore through the coating. Have tried mr sheen on one small corner as suggested by someone in a laminex show room. didn’t expect it to work! Any suggestions? The area is the size of a small plate unfortunately.

  113. A question for Dr chemical can you please suggest how to get rid of marks on the mirror wardrobe doors not just dust or streaks kind of shady marks that appear to be further in then just on a surface. Don’t ome off with ordinary window cleaner.

  114. Hi,

    I have a Colorbond fence running along the side of my house. We recently had an exposed aggregate path constructed next to the fence. The contractor has left a white concrete overspray over the fence and no amount of scrubbing will get rid of it.

    How do I clean the fence without damaging the paint coating? Even dilute hydrochloric acid is not recommended.

    Thank you.

    • Firstly hydrochloric acid is fine – even conc acid won’t hurt Colorbond. But another approach would be a heat gun – the metal expands at a different rate from the cement and it should break the adhesion and it will just flake off

  115. Hi there I would like a easy way to get the bugs that have splattered on the front of my car from doing country driving please.

  116. I want to remove 110 square metres of Couch grass – I dont want to use Roundup – have you any suggestions on how to kill the grass without using glyphosate

    • Yes – hydrochloric acid. I’d use it 1 part in 10, put it in a generic garden sprayer and just squirt the area liberally. You should see results within 48 hours. If you don’t more acid at higher concentration. And don’t worry – the HCl won’t poison the soil. There are natural chemicals in the soil that will neutralise the xs HCl, and in any case it’s volatile so it will evaporate. Depending on what pH you wanted the soil to be afterwards, you could spray it with a solution of bicarb afterwards, which would make it mildly alkaline.

  117. Good day Dr Chemical,
    We have burnt wet pine logs in out Jarrah wood burner, which has glass doors. The resin from the logs have splattered and melted into the glass.
    Can you tell if if can get this resin off please?
    Thank you Wendy Henderson

    • I’d just get more heat into it. With enough heat the resin will turn to charcoal, then burn off as CO2. I used to burn excess cooking fat (frytol) in mine, and the flue would actually start glowing red. And the glass was perfectly clear afterwards. So stoke it up hotter than the fires of hell and see how you go…

  118. Hi Dr Chemical
    I have some small rust spots appearing on my white car. I heard about using Rainex on rust. Would that work for me?

  119. Hi Dr Chemical,
    Is there a safe/non-toxic way to remove black mould that does not involve chlorine/ammonia/H2O2 type things? I used to use all these but was then diagnosed with bladder cancer and vitiligo both attributed to these types of chemicals. (as per academic literature). Is there anything safer that you know of? It has appeared on the ceiling / sloping ceiling so can’t really be scrubbed too much due to building age. Is it safe to do ourselves or do we require a remediation company?
    Thank you.

    • Oven cleaner works quite well. Use non-caustic oven cleaner to avoid any unpleasant fumes. It’s completely non-toxic

  120. Hi I used my iron on polyester now it’s stuck on my non stick iron can you please tell me what I can use to clean the iron. Thankyou

    • Get some washing soda from the supermarket and use it as a paste. Alternatively use a laundry powder as a paste cleaner with a kitchen scourer

  121. Hello Dr Chemical,
    Do you know of a product called Lo Chlor Tile and Vinyl cleaner and where I can buy it please?

  122. Hi Doctor Chemical
    This maybe a bit out of left field, but do you have a simple, home made solution for ant control? We have a massive ant invasion, in our lawn, gardens and pavers. More sand coming out of pavers than I can get back in, and a mess in my gardens.

  123. Hello dear dr. We had a framed print of an old aircraft hanging in our garage and mildew has appeared inside the glass and on the backing paper. I removed it from the garage and left it for a few days in the sunshine. I have now brushed the powder off and disposed of it in the garbage.
    When/if I get it clean I intend taking it to the local op shop.
    Can you please suggest what I should use now to remove the residue from the backing paper. Thank you.

    • Try metho. Or non-caustic oven cleaner. But just be careful it doesn’t damage the paper if it’s old. It shouldn’t – just spray it onto a small area first and check

  124. I made a single bed size embroiled quilt, which took 12 months to Finnish.
    It is made of cotton fabric with a wadding inside.
    I was going on holidays and placed items on the bed I intended to take.
    One of the items was a can of tropical strength insect repellant.
    Unfornately it leaked on my quilt which now has black marks on it.
    Do you know a way I could remove it.
    I really would appreciate it.

    • We’d better be a bit careful here. Insect repellant is not black, so could it have been caused by rust from the corroded can? That is, is it possible that the can was so old it has corroded thgrough and expelled the corrosion products?

        • Hmm. Not sure what that would be TBH. General approach – get some liquid laundry detergent and use it as a spot cleaner. Rub it in with your fingers and rinse. Might need to repeat it a few times

  125. I Dr Chemical

    I have silicon sealer on colorbond gutter, been there for years, has collected dust over the years is unsightly.

    How do I remove it.


  126. We had our dog throw up on our carpet one night when we had a thunderstorm, as he gets very agitated, and after using carpet cleaner there is a stain there. Is there something we could use to remove the stain?

  127. Hi Dr Chrmical I have lichen since having a limestone floor put in around the pool area. It’s taking over my house , cars , windows and even coming onto my house onto my floor tiles. I’ve treated it with diluted bleach then I used swimming chlorine !! As told it removed it effectively. But it’s getting worse.
    Thank you.

  128. Dear Dr Chemical
    I have just discovered your website. What a wonderful amount of information.

    My problem is that I have rust coloured marks on the exposed aggregate around the exterior of my house.
    I have tried quite a few things but nothing shifts it.
    Do you have any ideas?
    Many thanks!

    • It depends if it actually is rust (ie iron). If it is, hydrochloric acid diluted 1 part in 3 will get rid of it. If it’s not rust, try caustic soda flakes, wet them down, scrub in with stiff broom then hose off

  129. Hi Dr Chemical, every time I purchase a pair of black jeans I notice a strong odour. I’m sure this is from the dye that is used. Can you let me know how to get rid of the smell before I wear them. I have tried soaking in vinegar, hanging on the clothesline for 3 days and various other soaking in conditioner etc etc but the odour remains.

    • Not sure what smell you’re referring to, but air, air, and more air is the answer. You tried 3 days? Try 5, 7, or 9. It will eventually dissipate. If you were to attempt to do it chemically, soak it in bicarb soda – it’s an excellent general purpose deodoriser

  130. Once again I need your help…..What can I use to get rid of a white round spot (don’t know what caused it) on a pair of men’s suit trousers. Trousers are 50% Wool and 50% Polyester fabric. When trousers are laid flat on a table no mark seems to be there but when trousers vertical it shows! I have tried a damp sponge with water…….Hope you can help me again Thanks

    • Very hard without seeing it. It may be that it has been bleached by something. Wool is not a very robust fabric. Try some White King Stainlift Laundry prewash as a spot cleaner, but that’s all I can suggest

    • No. Use caustic soda. Sprinkle it in, wet down with a minimum of water, than brush in with a stiff broom before hosing off

  131. How do I clean a glass shower screen that has hard to remove water drop marks – the result of the tenant not cleaning it on a regular basis. Can I use a paste clesner like Gumption or Jif? Will that scratch the glass? Windex helps only a bit – the place whit water drop marks are still visible! Cheers Barbara

  132. Hi Dr chemical
    I have burnt on stain from cooking in the base of my stainless steel stockpot?
    I have had it soaking for a week in Coles cream cleaner and vinegar burnt stain not shifted.
    You site is great. Thank you Mary

  133. My name is Tiffany and I have two children, James who is 8 and Annika who is 6. I have always been cautious about plastics and my kids’ exposures but I just made a huge mistake!! I had our granite countertops removed and there was an epoxy strip joining two pieces which the person who removed it heated at 400F with a heat gun for about 30 minutes (my kids were in the basement the whole time) and even scraped away which did create dust (why did I do that!!!). I am 99% sure it had bpa and/or created dioxins as if it were the poly epoxy that contain styrene. I cleaned my cabinets with vinager and tried to forget about it. Then I realized that my glass cooktop was getting a film! I just cleaned it a few weeks ago and it was the same color as the epoxy !!!! I imagine, in my super safety concerned mind, that I have been exposing my kids to these fumes for two weeks, cooking on the stovetop. I imagine it is on everything from being in the dishwasher with my pots and pans that were on the cooktop: from my glasses to plates and silverware from the inside of my dishwasher. I have since cleaned the cabinets and floors with soap and water. The week after it happened I was sick, I thought I had the flu because I just felt beat, but now it makes sense.

    Now the worry is with our skin, I no longer sweating as normal when I work out. My forehead is greasy and my daughter is not sweating and she has the same film on forehead, temples and neck under chin as I do. My son has little pieces of raised skin for a month (almost acne but no color and one has caused a pockmark) on his chin and upper cheeks. I have stopped cooking on the cooktop. I felt a slippery almost plastic coating on nearby items including my teeth. Have I created a superfund site in my own home. I am willing to pay to have my kids and a sample of our home tested.

    How do we see if we are being reinfected by the dust in our home and most importantly, how do we get this out their bodies?

    If you can help or know someone who can, I would greatly appreciate your help. Any advice and if you could steer me in the right direction, I would be so grateful!!!! I could obtain a piece of the epoxy from my neighbor, what type of lab could identify contaminates.

    Also, in this madness I burned an oven mitt on the stove top (it was steaming, set off the smoke detectors) I put it in a plastic garbage bag and closed the lid and a few moments later put it outside. I think the smoke outside killed a plant in the winter, a small evergreen. It was left smoking while I stopped the smoke detectors. Dioxins? It was hefty. Ugh!!!! Such bad luck or many bad decisions on my part!!!

    Is this like bad mold and we need to get out to decontaminate?

    Sincerest advice would be greatly

    This is an image of the bottom seam where most of the heating was done they tried to scrape most off. It was very brittle. Again, thank you for your time.

    • I can set your mind at ease. Whatever chemicals were released by the heating of the epoxy will quickly dissipate and it’s just not possible that they are causing ongoing issues. BPA’s effect, it=f it exists, only occurs with repeated exposure, and it’s the same with dioxins (if they have actually been produced). My professional opinion is that most (if not all) of the symptoms you describe are psychosematic (sp?). That is, you perceive a risk, and imagine symptoms as a result. If you engaged a lad=b to test your home I can tell you now they wouldn’t find anything. So you can sleep soundly at night….

  134. Hi. I’m not sure if this is the right place to ask a question but here goes.
    I have travertine (sealed) in the shower base. I’ve tried a couple of products said to be safe on travertine to clean the grout, which I think was discoloured by the tiler’s poor workmanship. Also there appears to be some mould and I will probably have to replace the silicone to get it clean.
    Yesterday I popped in to a large local tile shop and was told that bleach could be applied. I asked if it would be best to dilute it and the answer was yes. Do you agree that bleach is ok on travertine?
    Confession, I have now applied the bleach with some success, so am wondering if I’ve done the right thing.
    I would appreciate your advice. Thank you.

    • Not great fan of bleach. Spray some oven cleaner on, wait a few minutes and then it’ll just wipe off. Use Ajax Professional Bathroom Cleaner (purple trigger pack) for the grout

      • Thank you for your quick response. I must say I’m very nervous of putting stuff on travertine. Using Oven Cleaner would not have occurred to me as I thought it would be far too strong. But is there a particular type of oven cleaner you’d recommend? Sorry to take up more of your time.

        One more thing if I may. Do you agree with Shannon Lush that the recommended amount of washing detergent/powder should be halved, even quartered?
        Thanks again.

        • Don’t make the mistake of equating the strength of a smell of a product with its ability to damage surfaces. Oven cleaner won’t damage the surface, but if you used a non-caustic oven cleaner it’d eliminate the fumes.

          As for Shannon Lush’s advice on cleaning (anything) you might as well ask a 5 year old. Her knowledge of the chemistry of laundry powders could be written on the back of a postage stamp. If you take her advice your clothes will be less clean than if you follow the instructions on the packet

      • Dear Dr. I purchased said Ajax product and before using it I read the label which stated it is not for use on terrazzo, marble, natural stone and such like words. (I don’t have it now as I returned it) I called the information line on the label and was told it is not suitable for travertine. Do you still stand by your recommendation?

        • Yes. They’re idiots.
          It won’t hurt any of those surfaces. I’ve used concentrated hydrochloric acid on marble to clean it and it didn’t damage it.

          • Oh that’s great. I thought I’d offended you by my last post. I also just had a look on CHOICE and that product got the highest recommendation.
            Would you kindly give me a recommendation on removing a few rust spots on Italian pavers in an outdoor area. I don’t know what material the pavers are made of except they are said to be rated non-slip. I have tried rubbing with a cut lemon with minimal success.
            Thank you Dr.Chem

          • Nope, I don’t get offended. Unlike some self-styled experts in this area, I know enough to know that there is a lot that I don’t know, and am happy to be proved wrong if appropriate. Rust is removed with hydrochloric acid, diluted 1 part in 3. Won’t hurt the pavers

  135. Hi, I have the stubbornist of stubbon stains on my carpet. professional carpet cleaner removes the stains and then after about a week they are back. Pleeeeeeeze help. What can I use. Spot cleaning seems to be the worst option.

  136. I have a bleach stain on my caesarstone bench and wondered if there’s anything I can do about it? I had a cloth soaking in bleach in the sink and one of my children put their cup in there and then removed it and stood it on the bench without me realising. The cup must have stood there for a while as I now have a ring on the bench and can’t remove it. Any suggestions please? The bench is white marble colour so it’s not too noticeable, but I know it’s there!

    • No I’m afraid not. Bleach is a very strong oxidiser and will irreversibly oxidise many things if given a chance. In this case it’s found something coloured in the benchtop to oxidise and it cannot be reversed

    • I had the same problem and solved it. Spread a thin layer of White King gel over the complete surface until you see the ring disappearing, then wipe away all the gel with fresh water. This only takes a minute or two. The manufactured stone discolours over time, and needs a freshen up every now and then.

  137. Trying to keep rabbits out from under my car..will mothballs left on the ground on brick pavers stain them..or is there something else I could use that won’t damage the pavers?

  138. Hi, my daughter dropped a cup of hot chocolate on my wool carpet. I have tried to remove the stain but it remains. Please help!

    • I reckon the Preen Vanish powerfoam would get that off. Alternatively, spray some White King Stainlift on it and leave it – the enzymes will prtobably do the business

  139. Hello Dr Chemical,

    How would you recommend cleaning a white fibreglass caravan roof that has been exposed outside for many years and has become chalky, porous and stained with mould and mildew? Also, would you recommend painting it afterwards, and if so, with what?

    Thank you!

    • Mould and mildew can be removed with oven cleaner. Unfortunately fibreglass is not UV stabilised and degrades with long exposure to the sun. If you were going to paint it I’d ask a motorcycle or marine painter – they paint on fibreglass all the time and would know what to use

  140. I have a dark brown leather jacket which has become covered in white mould from being in the wardrobe since last winter. How can i kill and remove the mould and stop it returning without damaging the jacket or affecting the colour and do i need to afterwards treat it with anything to protect it?

    • Spray some non-caustic oven cleaner on it, wait a minute, and with a bit of luck it should just wipe off. Best preventative treatment for leather is Dubbin

  141. Hi Dr Chemical, the husband is trying to clean and polish two old and one reasonably new wheel rims in order to shine up for sale. He has used brasso, wet and dry paper and degreaser, they have not ended up lookig that great. Any other suggestions please???

  142. Wondering how to get latex out of clothing, can you help me? I am a beauty therapist and got some latex mask powder on my shirt which has set there when I washed it

  143. Hi.
    I was wanting to know how to remove a smell from carpet. My youngest daughter was sick and vomited on carpet. I applied no-vac odour remover however now the room smells of this product.

    • The residual smell comes from organic compounds. Best way to remove them is with heat. Either use a steam cleaner if you have one, or at a pinch blast the area with some hot air from a hair dryer. But I’d expect the smell to dissipate pretty quickly anyway

  144. Hello, I have stained the plastic trim around my kitchen cupboards and drawers yellow with a solution of bleach. I’ve tried to remedy this with peroxide, lemon juice, bicarb and vinegar. Can you help as it makes my kitchen look old before its time. Thanks for your time

    • Unfortunately bleach is a potent oxidiser that has just this very effect on plastic. The only thing you can do is to use an abrasive of some sort to scrub off the upper layer. Get some fine grade wet-and-dry from the hardware store and have a go. Use it wet and you should still finish up with a smooth finish

  145. Hi Dr Chemical,
    I’m overwhelmed with choice when I buy clothes washing detergent at the supermarket.
    What is your recommended family clothes wash detergent for a front loader and warm washes?

  146. Gidday Dr Chemical how do i get white paint off a rubber sandel sole.I’m not sure if it is oil based or water based.

    Thank You


  147. We have coffee coloured bathroom floor tiles (not shiny) but when I cleaned with Easy Off Bam it left some white cloudy marks on a few tile edges. I did wash everything down with clear water after cleaning but obviously not well enough. Please can you help ? Thanking you

      • Thanks Dr Chemical…….I bought new scourers ( which can also be used on my Scanpans ) and together with the laundry powder paste worked just fine on the tiles.

  148. My sister’s husband has early dementia. While she was out of town last week he cooked the something (won’t tell) in the oven & either it spilled over or started a small fire – he won’t give an answer as to what. Apparently he tried to clean up the mess. My sister opened the oven yesterday & found the entire bottom, door & 1/4 way up the sides are RED & look a bit like a smeared mess. Her husband said he tried to clean it with something under the sink but can’t remember what. Later he implicated he might have tried more than one thing. There is dish soap, window cleaner, glass cooktop cleaner, 409 multipurpose cleaner & several other things under there. Would it be safe to try the self cleaning feature without knowing what is on there?

    • Yes – the self-cleaning feature simply applies lots of heat to burn off oil and fat. In a perfect world it’s all converted to CO2. If other things have been used in there, there may be inorganics present that won’t be removed by the self-cleaning cycle, but there’s a good chance that what is left over afterwards will flake off and be easily removed afterwards

  149. Could you tell me how to remove timber stain of wooden table and chairs off white concrete with pebbles in ? Thanks

    • Use caustic soda. Sprinkle some flakes on, wet it with a minimum of water, rub in with a stiff brush then rinse off

  150. Hi Doc
    I have have small orange juice stains on a curtain spread over an area of 3 feet by 3 feet …have been eating juicy oranges close by and the stains have probably been there a couple of years.The curtains are cream,bought to hang with a thick sun block fabric on the back.Do you have a remedy for this ?

  151. Dear Dr Chemical . can you please help me I would like to stain a piece of rosewood with ebony stain but the rosewood has some sort of oily type sealer I have tried metho. turps acetone and naptha but none of these work any suggestions. Also I would like to remove a glued on label without it leaving a white mark on the wood.
    Many Thanks

  152. Do you have a solution for getting rid of the pesky ants that undermine pavers? The commercial products seem to work for a day and then they are back with a vengeance!

  153. I have dark grey cement pavers with a white border… How can I bring them back
    to a clean condition.. I have tried to high pressure clean them but not much difference to look at them.. I have garden next to these pavers so I dont want to
    poison the plants and kill the lawn.

    • Get some caustic soda and sprinkle the flakes over the pavers. Wet down with a minimum of water, then use a stiff broom to rub it in and push it around for 5 mins. Then hose off, and a lot of the grime will come away. HP will bring it up even better

  154. This might be more of a physics question but… My feeble kindergarten knowledge of physics tells me that when you heat matter up to very high temperatures, so much energy is present that the normal structure of atoms and molecules breaks down. This means you no longer have, say, nitrogen or carbon etc with their distinct arrangements of electrons, protons and neutrons etc. Instead you simply have a disorganized collection of sub-atomic particles and the resulting ‘stuff’ is known as plasma rather than any specific elements.

    Fair enough but I’d like to know what happens when plasma cools down. Does it re-organise itself back to its original material? If so, how does it ‘know’ what it was? It seems like taking all the individual letters of a novel, letting a tornado mix them up and then expecting them to all re-assemble themselves back into the original novel by sheer luck.

    Surely I’m misleading myself here.

      • OK – thanks for your honesty. I’ll try getting Dr Karl to address this. I’ve already asked two physics undergrad students and they don’t know either.

  155. Hi Dr Chem, Would appreciate advice on cleaning a sisal rug (approx.2.3m x 1.6m) It is vacuumed regularly but is discoloured by a greyish smudge in one corner caused by dirty feet or shoes. the area affected is about 50cm x60cm and the rug colour is similar to oatmeal or wheat. I believe it is not wise to use water as the sisal is very absorbent and likely to watermark. Look forward to your your advice. Brian.

    • I’d be trying the Vanish carpet powder on that. Failing that, there’s a place in Canning Vale that clean rugs that are dropped off to them (forget the name)

  156. Dear Dr Chemical, my dad’s pen leaked on his woolen jumper. Unfortunately he took tissue and rubbed it off and we have been unable to get the stain out.

  157. Hi Mike. Following yr program this morning on Curtin, I’m prompted to ask about leaf stains on the bottom of a fibreglass pool. Your thoughts appreciated.

    Thank you


    • Get either some Washing Soda or laundry powder, sprinkle a generous amount on, then wet it to a paste and rub in with a scourer. Or oven cleaner might work too

  158. What a great comment on today’s Jenny Seaton. show, about the bore stain, on a wind screen. When you do not know Just bullishit your way throuht it
    you are a Fake You my never have heard of Oxalic Acid and as such You are a fraud
    Lying C….

    • Not that simple I’m afraid. Although oxalic acid will remove bore stains, the reaction product is insoluble and highly adherant ferric oxalate, a pale green powder. I’ve tried it to get bore stains off dark-coloured pavers and bricks, and have found the pale green residue virtually impossible to remove, even with HP water. Presumably the strength of the adherance is due to the fact that it is formed in-situ, and therefore has intimate contact with the substrate. It’s fine on light-coloured surfaces like limestone or limestone-coloured pavers where you wouldn’t notice it, but if you used it on your windscreen you’d probably find a pale residue when it dried that would be impossible to remove and you’d have to replace the windscreen. Stronger acids can be used to get borestains off glass, but I wouldn’t advise a non-professional to use them as that can cause a great deal of damage in the wrong hands.

  159. Please can you tell me how to remove stains from a caravan awning that has not been in rolled out for a year but has been under cover. Thanks Manus.

    • Any particular type of stain? General approach sprinkle some caustic soda flakes on it, wet it down with a minimum of water, then brush it around with a stiff broom and hose off

  160. Hi dr chemical, My slate floor needs cleaning and resealing. What product should I use to clean the slate and grout first, then what product to re-seal. I don’t know what sealant was used initially. I can only tell you it has a matt finish. Can I do this or would it be better to get a professional.

    Many thanks


    • You can’t go past steam cleaning for that – I wouldn’t use any chemical on it. And I’m afraid I don’t know a lot about sealers

  161. Hi there!
    My 3 year old Son was recently diagnosed with Lukaemia, I’d love to know common household products that contain the chemical Benzene and/or other affiliations that you know for around the home, e.g. Pest sprays etc.

    Any information would be great! Thank you! #Rally4Ryder xxxx

    • The only product that he could be exposed to that contains benzene is petrol. Some solvents like White Spirit have a little bit (0.1%), and the only product inside the home could be Mr Sheen as it contains White Spirit

  162. Hi there, I’m hoping you can advise me the best way to clean the steel burners on a gas cooktop. They are neatly black ! I’ve tried good old elbow grease, bicarbonate of soda with vinegar but not getting very far. Any help would be appreciated.

    • Unfortunately bicarb + vinegar will clean almost nothing. They actually neutralise each other and effectively eliminate whatever cleaning properties they may otherwise have. I’d use some Mr Muscle oven cleaner on that. It sprays a rigid foam that will stick to the burners. Let it soak for a good 5 minutes and it should then come off pretty easily

  163. Me again.

    Two more questions.

    Any hope of removing balsamic vinegar stains from cotton clothing?

    Also, what is the difference between sodium carbonate, sodium percarbonate and “disodium carbonate, compound with hydrogen with hydrogen peroxide (2:3)”?
    I’ve been looking at material safety data sheets to try and work out what is in some of the products I use, to be able to better judge the value for money of different brands and also to see if it is possible and cheaper to buy the individual ingredients in bulk, and now I’m so thrilled I’ve found your blog. I have only read a little bit so far, but enough to have just fished out a Shannon Lush cleaning book off my bookshelf which I will promptly dispose of.

    • Balsamic vinegar will be removed with either White King Stainlift or Preen Oxy-Action. In both cases, use as a spot cleaner. Spray on, rub in with your fingers for a good 3 or 4 minutes, then rinse and rpt if necessary

      Sodium Carbonate is Na2CO3 , otherwise known as Soda Ash or Washing Soda, and is the basic ingredient in most laundry and dishwasher powders. Also good for dishes. It is an outstanding general purpose household cleaner – I’ve got some blog posts on it somewhere. The other two are just different names for sodium percarbonate 2Na2CO3.3H2O2, which is a laundry bleach as it releases oxidising peroxides (H2O2).

  164. What differences are there between regular and plant based dishwash and laundry products? Are plant based products less effective, and if so, why?

    Also, do you have an opinion on whether plant based products are better for the environment? If they are the same chemicals but of plant origin, I can’t see that the impacts from using them would be any different to the regular products (everything seems to be biodegradable, phosphate free etc), in which case it comes down to the source materials and manufacturing processes.

    • I’m not aware of any plant-based laundry products (at least in Australia). Happy to look into it if you have some more details

      • The dishwash and laundry products I’m referring to are the ones marketed as environmental friendly, they have written on them “plant based ingredients”. For example the Earth’s Choice range of products all say on them “plant based ingredients”.

        But they seem to have the same main ingredients as everything else, sodium carbonate etc. I’m wondering what makes them different? Are the main ingredients somehow made from plants and the same main ingredients in other brands aren’t? Are they just adding a token amount of plant based ingredients to essentially the same stuff as everyone else sells and calling it environmentally friendly?

        • OK I’m with you now. I’m pretty sure that range of products come from Reckitts Benckiser. By plant-based they probably mean that they are using soaps made from vegetable oils like palm oil, or something similar. This is how people used to make soaps in days of yore. They would work, but unlike the synthetic detergents that are in other products, their effectiveness would be reduced in hard water. But it’s a moot point, as all the synthetic detergents used thesedays are biodegradable anyway

          • Nature’s Organics is AUSTRALIAN OWNED and made. It is a solely owned FAMILY company based in Ferntree Gully Victoria. NOT IN ANY WAY connected with Reckit Benkiser or any other large multinational. I am disappointed you have published this when you have only to look at their website. Had you done so, you would discover all about their processes and what their products contain. I am not a member of this family, just in case you were wondering. You have so much great advice on this site, it’s a pity you couldn’t check a simple fact.

          • It is very often the case that when multinationals market a brand under a non-obvious name for the purpose of making a buck they attempt to conceal the fact. For example, when Reckitts bought Pea-Beu off Ciba-Geigy in 1985 thay wanted to conceal the fact that it was made in the same factory as Mortein. As luck would have it, the site was on the boundary of two suburbs, so they chose different streets for the addresses, and therefore different suburbs.

            In this case, Earth Choice most certainly used to be a RB brand – I remember that ACA once did an expose on them, and exposed some of their dodgy claims. It appears, at first glance, that they have now sold the brand to Nature’s Organics, which is clearly a much better fit.

  165. Could you please tell me how to remove the stains from sunscreens left around the neckbands, etc of t-shirts ( cotton?) – no luck with prewash sprays/ soakers/ biozet washing powder. thank you

    • I’d try acetone on that. Let me know how it goes. Put some in a bowl, and dip and withdraw and rpt. No need to scrub. I think it’ll dissolve. Metho also might work, but it won’t be as good as acetone

      • Aha, I was just about to post this same question. I’ve been trying to research this for a long time now. I’ve tried various spray on stain removers, soakers, vinegar, lemon juice, even the original Jif cream cleanser and leaving the garment in strong sunshine. (The Jif worked to some extent).
        The diluted vinegar lessened the yellow, but now it just looks dingy, after soaking it (again) in neat white vinegar.

        The strange thing I have found is that the yellowish stain is not there before laundering, but when I hang the garment on the line to dry, the yellow has appeared. Another strange thing is that sometimes if I leave the garment (dry) for a while, say a week or so, the stain disappears. However, not always.
        I resorted to contacting EGO and Neutrogena and was told that all sunscreens will cause the staining. The advice was to make sure the lotion dries completely on my skin before donning the shirt.
        So, dear Doctor, do you know of a sunscreen with SPF 50, preferably one that’s a moisturiser for the face/neck, that will not cause this staining in the first place?

        Meanwhile, I’m off to buy some acetone.

  166. Hi Dr Chemical

    do you have a cleaning method for removal of mould stains on a leather chamois? I have tried hot water with white vinegar and sunlight but the stains are still there. I use this chamois for drying my shower screen.

    • No I’m sorry – I had the same problem on a pair of jeans. Couldn’t get it out no matter what I tried. They were consigned to the garage.

  167. Hi dr chemical, I accidentally over sprayed bam oven cleaner on to the grass whilst cleaning the racks outside (a lot of over spray) how can I make this patch of grass safe for animals I hosed it down will this make a difference?

    • If you hosed it off then it’s fine. And anyway it’s unstable in air and quickly degrades to harmless compounds

  168. Recently purchased jeans have a strong chemical small, similar to diesel. Normal wash cycle has not removed it. Any suggestions. Cheers Jenny

    • Hang it outside in fresh air for a couple of weeks – there is no substitute for fresh air for this. If it is diesel, or anything like it, get some Kenco degreaser from bunnings and use it as a laundry prewash

    • Oven cleaner. Spray on and wipe off. Alternatively put some metho in a generic spray bottle and that’ll work well too

  169. Hi Dr. Chemical
    A Liqudambar tree on my neighbour’s property is sending roots under my concrete driveway that travel 10 metres to my garage and under the house, lifting and cracking the concrete in the process. I’ve tried weed killers to stop the roots to no effect. Any ideas?

    • Yep. Go to the hardware store and buy the strongest solution of glyphosate you can get. I think yates sell a 1L bottle for about $12 that has a concentration of 360g/L. Take no notice of the brand – the glyphosate in Roundup is exactly the same as the glyphosate in every other brand. Then get a wood drill and drill as big as a hole as deep as you can in the root. Then tip the glyphosate in straight away (within a couple of minutes) before the pores close upon exposure to the air. More holes is better. It will begin to kill the tree in a couple of weeks. And no one will be any the wiser….m And there’s no way to kill the roots without killing the tree.

  170. Hi Dr Chemical.
    Yesterday I was sneaking a Maccas frozen raspberry into the movies inside my ligt tan leather handbag and tripped on the step, spilling the drink inside and on the outside of my bag. Gaaaaah!!
    I have carefully washed the fabric lining, but need some help on how to remove the (now dried) stains from the outside of my bag. Please help!

  171. Recently my son and I used a heavily diluted mixture of muriactic acid to scrub his basement concrete walls – we waited about 3 hours and the painted the concrete with a waterproof paint.

    I neglected to wash down the wall before painting.

    Must I remove the paint to wash the walls and then paint again ?

  172. Hi I have a pinkish dust all over my bath after removing the grout and don’t know what it is, I’m hoping I haven’t hit the villa board or something .

  173. Hi Dr Chemical,

    Can you tell me how to remove a rust stain from the toilet bowl please.

    One of my sons dropped a round battery into the toilet which sat there for a couple of days before I found it and removed it, but it has left a rust stain that is under the water line.

    Thank you

    • Tip half a litre of hydrochloric acid into it and you should see it dissolve after a few minutes. Then flush several times to flush it all away. Or use some wet and dry abrasive paper (with a glove) – it should rub off pretty easily

  174. Hi Dr Chemical, How do i get rid of the urine smell on a carpet mat ? Had it cleaned twice ( carpet cleaners) and the smell is still there.. can’t see what its made of but it says professional dry cleaning recommend. Sure this will cost a fortune. Can you please advise me what to try. Can’t see stains but strong smell still.

    • Use vinegar. It will neutralise the amines that cause the smell, and create its own individual pleaseant smell. But if it’s on a mat the best option is to put it outside in fresh air for a week or two. The smell will eventually evaporate

  175. Electro Chemically Activated water is apparently environmentally friendly and is a great disinfectant, that is Hypochlorous Acid. Why is this a “green” product and normal Chlorine is not? If you dissolve Chlorine it will also form Hypochlorous acid under the correct pH. Is that also environmentally friendly.
    It confuses me, can you please help.
    Thank you
    Kind regards

    • By “electrochemically activated water” you are apparently referring to seawater that has been through an electrochemical cell where the chloride in salt water is converted to chlorine. This will convert to hypochlorous acid at pH 8.2 to 8.5 which is the species that reacts with nasties in the water, which is what you want. Bleach (sodium or calcium hypochlorite) works by exactly the same mechanism, also producing hypochlorous acid in this pH range. So I’m not sure what you intend by “environmentally friendly” but there is no difference between the two. In both cases the chlorine compounds are unstable and will eventually degrade in light to salt and water

  176. Good afternoon,
    Could you please suggest how to remove a large amount of tannin stains from outdoor off-white colour ceramic floor tiles? I’m not sure what type of timber has caused the staining.
    Thank you,

  177. Hi Dr Chemical

    Can you please tell me how to remove the ink stain from white furniture? I had a catalog sitting on top of a white painted wooden cupboard and some oil or something leaked on it, don’t know how long it was sitting like that but the ink from the catalog has transferred to the paintwork, don’t know what to do or how to remove it. Please help!

  178. Hi Dr Chem,

    What product/s would you recommend for cleaning heavily watermarked pavers?
    Have already tried high pressure hose and water = nothing
    Hydro acid scrubbed in and then high pressure hose. Some shift in stain

    • You want caustic soda. Sprinkle flakes on, wet them with a minimum of water, then rub in with a stiff brush. HP cleaning would then bring it up a treat

  179. Hi Dr Chemical,
    I am finding it difficult to remove gecko poo from my cream rendered outside walls.
    It appears to stain the walls and too much pressure affects the render. I have tried detergent and hot water with a soft scrubbing brush but it doesn’t remove the stains.
    Thank you

  180. Hi Dr chemical,

    Could you explain why nervous sweating smells so much worse than normal sweating? For example, when my partner sweats in his t-shirt due to nervousness, rather than being hot, the smell is very strong, acrid almost and won’t come out in the wash. Where as any other sweating will easily come clean in a normal wash.

    • That’s above my pay grade, I’m afraid. It’s entirely possible that a different smell is generated, but I don’t know why. But it shouldn’t effect washability. What temperature do you wash at and what brand of detergent do you use?

  181. Hi, I have a mustard yellow coloured leather brand new banquette (bench seat) in my new kitchen. It already has some stains from the builders!! I know one of the stains is from kitchen detergent, not sure about the rest. Please advise the safest method to use without risking doing more damage. Many thanks – I have asked Shannon but was dubious about the reply. She suggested the method would depend on whether the leather was a type that absorbed water or not.

    • A general approach to cleaning leather, without knowing exactly what the stains are, is to use Dubbin. It’s generally available from supermarkets or hardware stores, and will help rub out most stains. But if it’s mustard yellow, it means that it has been dyed somehow, and it’s possible that the stains have actually reacted with the dye somehow, in which case there’s not much you can do.

    • Do you mean remove it from your clothes? You don’t need to – hydrogen peroxide is unstable and decomposes with exposure to light into water and oxygen. By the time it gets to the shop where you bought it, it will all be gone

  182. Hi, love this column, lots of good info. What can you suggest for cleaning and then protecting the white seats (vinyl) I think on our boat.
    Also there is a musty smell in the carpet, what is best to clear it up. I have bicarbonate soda sitting around to absorb the smell, but it’s still there.
    Thanks heaps.

    • You can’t beat Mr Sheen for the seats. For the carpet, there is simply no substitute for air, if it’s the carpet in your boat and it can be removed. If it can’t then heat, and lots of it. Put a fan heater in there and close the doors, but leave a window cracked open so the moisture can escape. With enough time it will evaporate and the smell dissipate

  183. we have a smc fibreglass shower base that we use a enviromentally friendly cleaner on we make which is white vinegar,epsom salts and eucalyptus oil. and the shower base is turning a vivid blue any ideas to return it to white again.??

    • Use a non-caustic oven cleaner on it. I wouldn’t be using eucalyptus oil on fibreglass – it’s porous and will soak in. For ongoing cleaning use any acidic bathroom cleaner (such as Ajax Spray and Wipe with Lactic acid)

  184. Hi Dr Chemical
    I am really hoping you can help me had a new linoleum (timber imitation) floor laid unfortunately we place a rubber dart mat down and have found the bitumen has left a yellowish stain on the Lino …..ruining our new floor
    Any advice is greatly appreciated

    • soak a rag in metho and sit it on there for a couple of hours – that should shift it. Failing that, try washing soda, used as a paste (add water to it) with a mild scourer

    • Use a stronger acidic bathroom cleaner (Ajax Spray and Wipe with lactic acid). If that doesn’t shift it, then the glass may have been etched by the soap scum, in which case there’s nothing you can do about it

  185. How do I rejuvenate the finish on exterior hard black plastic trim on my car? It has taken on a sperkly, chalky finish, like it is breaking down thanks to UV. It is also on my roof rack mounts and the windscreen wiper arms.

  186. A friend spilt plunger coffee on my heavy white linen tablecloth. I have soaked the stained area in cold water with some Sard Wonder Oxyplus, Power Stain remover, which has a eucalyptus smell. Can you suggest anything more effective and should I then machine wash it (Front loader, Omo Sensitive)?
    I heard you on Curtin 100.1 FM…. brilliant!
    Many thanks

    • The problem is the temperature. It needs to be about 40 deg for any of those products to work. Use some White King Stainlift. Spray it on, let it soak for a while, then wash at about 40 deg (warm on some machines, hot on others). 40 deg is the optimum temperature for the enzymes to work. If that doesn’t work, use it as a spot cleaner, rubbing it in with your fingers. Your fingers will create the right temperature to activate the enzymes

  187. Hi Dr Chemical,
    You are so helpful, I wish you lived next door!

    A couple of days ago we had a water leak coming in from our roof; the carpet (not sure if synthetic or wool) now has a large stain (the water in the bucket was slightly dirty yellow colour). It is now almost dry. Any suggestions to try and remove the stain? Or, should we just call the carpet cleaner. I notice from previous posts you refer to high pressure steam cleaning with high vacuum extraction; would this be suitable? Thanks, Frankie.

    • That should be pretty easy to get out with any of the off-the-shelf carpet foams. If you’re in Perth the best carpet cleaner I have found is Clean Underfoot. If elsewhere, and you need to get it professionally cleaned, don’t waste your money on anyone that doesn’t turn up with a van or truck with a big machine in the back and long hoses to get in your house. The portable units are a waste of money

      • I have been cleaning carpets for over forty years and have only used portable machines ( never owned or used large machines in van ) never had a problem removing stains, getting new clients by recommendation, cleaning the carpets for the same house owner for several years, I have cleaned carpets in Pubs, Schools, Commercial Offices and
        hundreds of Private Homes, perhaps the problem is not with the machine but the technician?

  188. I have white quartz countertops in my bathroom. Around the faucets, I have a brown stain forming. I want to know what I can use to clean it without damaging the quartz. Traditional cleaners, acetone, and vinegar haven’t done the job. I watched a tutorial using Harpic to clean it but I’m unsure if this will hurt the quartz. What should I use?

    • Harpic won’t hurt it, and I can’t think of any common chemical that will. The brown staining is rust. Get some citric acid from the cooking aisle at the supermarket and use it in a paste (add some water to it) with a scourer. That should shift it but a bit of elbow grease may be required. If that doesn’t work, try some Oxalic acid, although I’m not sure where you’d get some from. Hardware stores used to sell it, but it’s getting a little hard to get these days. Or the other approach is use a mechanical approach (as opposed to chemical) and scrub it off with Ajax Powder Cleanser (or Bon Ami)

  189. My boyfriend cleaned the bathroom with a product that contains 80% citric acid. He didn’t realise it wasn’t suitable for our bathroom tiles as they are limestone. Now there are several white blotches. Can you advise a solution to reverse the colour back to the cream / egg shell colour?!

    • You can’t reverse it, but it will return with time as it ages. The white colour is simply the clean limestone with the outer (aged) coating removed. I’d suggest you do the whole surface and then let it yellow uniformly with time

  190. Hi Dr Chemical. How can I get water marks off my windows? They have been there a long time and are like water drops with a well defined white edge deposit. I have tried everything that I have been recommended (Ajax Spray n Wipe Bathroom, Orange Power, Hydrochloric Acid, CLR, natural cleaners) without any success. Any suggestions please?

  191. Hello Dr Chemical
    I hope you can advise me how to clean the plastic inflatable pool. I have removed the water but the bottom of the pool is covered with black/brown stuff!
    With thanks in anticipation

  192. Hi Dr Chemical – I have a linen/cotton blend dress which has a navy background with large white spots. I always hand wash the dress in lukewarm water but the navy dye bleeds into the white spots. I have put salt and vinegar in the water to stop the dye running but no joy. Any suggestions

    • If you use a premium brand (like OMO) they have antiredeposition agents that stop this happening. Or you can buy colour absorption swatches that you throw in with the wash that also work

  193. How do I remove a rust mark from a metal stud on my white denim shorts when they were left soaking in a bucket of water with Napisan for a couple of days?

    • Get some citric acid from the cooking aisle in the supermarket and rub it in as a paste and leave it to soak for a while. Rinse and rpt as required. If that doesn’t work get back to me and I’ll give you other options

  194. We have recently had a bathroom renovated. During the process of installing the new toilet a quantity of water leaked from around the base. I was told to leave it overnight so that the leak could be assessed. The problem was obviously sorted and job completed. However there remains (on dark grey/brown Cer Asia vitrified porcelain tiles) water marks where the liquid settled. The bathroom company don’t seem to be able, nor want to help. I have only attempted cleaning with Selleys Tile Clean but the marks remain. Can you suggest a solution? Thank you

  195. hi dr chemical, my male dog wees in one particular area under my patio,,,, it has now stained or discoloured the brown porous concrete pavers,,,, they have become almost white where he wees on them,,, have tried neat white vinegar,. left soaking for 10 minutes then hosed off,,,, with a pressure cleaner ,,,but when the pavers dry they still have the same faded white ish look about them,,thanx for your amazing remedies

    • Nothing you can do I’m afraid, once the colour has been stripped. To deter the dog I’ve heard that Vicks Vaporub can help. Leave an opened bottle in the area where he normally wees

  196. Thank you, thank you for your advice after I had yellow stains from a prewash spray on a caesarstone bench top . I sprayed with oven cleaner, had to wait a few minutes, wiped off, then like a miracle & I mean miracle, stain gone !!
    Am busy reading all your other hints now. Thank you again.

  197. Hi there, I just had a dark concrete path poured that meets a set of stairs made of Austral retaining wall blocks in a light sepia colour. Unfortunately, the concreters got some dark concrete on the block steps. Any ideas on how I get it off without ruining the blocks? Thanks.

    • You’d probably find that the adhesion of the cement to the block steps is pretty poor. Blast it with a heat gun, and you’ll probably find it’ll just chip off. You could help it by getting a small hammer and tapping on the dark patches – that should help break it up

    • The smells from vomit are caused by a class of chemicals called Volatile Fatty Acids (VFAs). The solution to it is a non-caustic oven cleaner. Spray it on, wait a minute or so, then wipe up with a wet rag or paper towel. Repeat as required and you should remove both the vomit and the smell

  198. HI Doc,

    I have a doctors surgery i clean that has vinyls flooring – quite old flooring id say from when it was built in the 70’s or something. There is discooluration on the floors – lighter and cleaner where not much traffic occurs, and darker dirtier looking in high traffic areas – have tried oven cleaner and ammonia but this hasn’t worked. can this old discolouration be removed?

    • I’m afraid not. The reason that vinyl flooring is cheaper is for this exact reason – it has poor chemical resilience and degrades with time. If you’ve tried ammonia then there’s nothing more you can do

  199. hi,
    I used a combination of dishwashing liquid & vinegar to clean a glass shower screen, however upon drying it has left a white film which I have found impossible to remove with a rang of commercial cleaners or neat vinegar. I haven’t tried any of the cream cleaners (JiF/ceramic cooktop cleaners) for fear of scratching the screen. Any suggestions ??

    • If you have tried something like Spray & Wipe Bathroom and it’s still there, then I’m afraid you’re out of options. Although it might look like a coating it’s actually the opposite – the glass has been etched. The only option you have is to attempt to fill in the cavities and cover it up. Use of Mr Sheen or automotive polish (with silicone) might help. Or there’s another option (that I haven’t tried). Go to Bunnings and tell them you want a product for sealing cement or bricks or slate. Some products say they have a “wet look”- if you painted one of these on the glass there’s a good chance it’d fill in the cavities and restore the clear look. It’s only an educated guess, but the chances are that it wouldn’t look any worse than it does now

  200. I have tent on my windows to keep the sun from fading my “carpet in my dining room, its beginning to look dusty what do i clean the windows with that wont harm the tent

  201. Hi , somebody spat on the side of my wife’s car, it has metallic paint , and i have tried everything to get spit stain of but nothing works any ideas,

    • Your best chance is metho, or maybe acetone (soak it for a little while). But it might not work – modern paints are very resilient.

  202. Our Silver Chain home help suggested oven cleaner for the black in grouting and occasional mould if the rubber mat has been down for a few days. Would love to try that but we have a bacterial sewerage system . Is the oven cleaner toxic so it will kill the bacteria.
    Also, Any easy way for an OLD lady to clean the oven?

  203. Hello I live in a house that is 20 years old and by the beach. The powder coating is now peeling off and I would like to repaint them as they are still in good condition however I am not sure of the best way to do this should I strip them right back and what sort of primer or chemical should I use to make sure the new paint job lasts the distance I have asked at a couple of paint shops but am getting conflicting advice. Much appreciate your help. Ana

  204. I’ve just read your global warming/carbon dioxide column at Principia Scientific. I asked a physicist friend (who is a global warming alarmist) to tell me what was wrong with your reasoning, and this is what he wrote: “His calculation is correct but he is doing the wrong calculation. He is doing a calculation of thermal conduction from the gas CO2 into the ocean. Where the real effect is that the atmosphere is trapping the infrared radiation and re-emitting it in all directions some of which goes back to the ground and the ocean. Water is a very good absorber of this infrared radiation.”

    This is all way out of my league, but I wonder if you could address what he has told me, and either re-validate your position, or poke a hole in his. Thank you!

    • No – he is right. That article was a far too simplistic approach to the issue. The mistake that I made was attempting to prove something. In general terms the position of the sceptic (which any scientist should be) is to ask others to substantiate their position by proof. Those who claim that manmade CO2 is heating the climate have not done so, and I don’t think they can

  205. I threw my girlfriend’s helium filled balloons in the shower and they went flat instantly they just sank to the floor.. what was it about the hot water that made the balloons seem to lose their helium or ability to float? As I wrote this post they started to slowly float back up are they zombie balloons? Seriously though I want to know

    • That’s a weird one. I need more details – when you say they “went flat” do you mean they visibly deflated? And then when they began to float again did they visibly expand in size?

  206. Hi, was wondering if you could tell me how to remove paint from a school shirt, not sure what paint was used at the school for their art class.

  207. Hi

    We have clear vinyl patio blinds that have become stained – robably from rainwater while rolled up – how can we clean them.


  208. Hello Mark. I phoned you about a week ago when you were on Curtin Radio to ask how I could remove yellow stains from an old, but very good damask tablecloth and napkins. You suggested I use something that sounded like ‘BIZET’ liquid or powder. Could you tell me the correct spelling please, or product name if I have it completely wrong. No-one knew what I was talking about in the supermarket. It would be wonderful if the stains can be removed as it was my mother’s tablecloth, and I would love to be able to use it. Thank you for your time.

  209. I have a stain in my bathroom basin. The basin is white plastic or fibre glass and the stains looks like a cigarette burn but its not a burn but we can’t remove it. How can I remove it?

  210. How could I clean a red stain off my white leather Lounge? The red stain is from a red tinsel Christmas decoration that was pushed into the fold of my lounge (by one of my grandchildren).

  211. Mark,
    Your article on carbon dioxide and global warming is excellent just one correction. You state that ice caps melt in summer. Ice caps can’t melt in summer. Ocean ice around ice caps can melt but they are not ice caps. Ice caps are on land – Antarctica and Greenland -90% in Antarctica – caps are 1000s of meters thick in ice and average summer air temperature dont get above 0 degreesC. The 19million sq. km of floating ice around antarctica and the arctic ocean melt from beneath – from warm water currents. When they melt each year they return the water to the ocean without any change of volume to that the ice displaced.
    The highest ice at the South pole is a few meters different to the height of Mt Ararat where the Flood in Noah’s day rose. Coincidence?? I think not.

  212. Topic: Suboceanic volcanoes.

    You mentioned in a (great) article that CO2 could not heat the oceans water…in short, my question is..What about sun-oceanic volcanoes. I won’t elaborate as I’m certain you understand.

    Looking forward to your response

    • Sorry, I don’t know anything about those. My calculations were simple back-of-the-envelope calculations that show that, according to AGW theory, 0.4g of CO2 can heat a ton of water. I don’t think that’s anywhere near feasible. In particular, most people don’t understand the fundamental difference between a real greenhouse and the atmospheric greenhouse effect. In a real greenhouse, a highly dense material (glass) transfers heat to a much less dense material (air). In the atmosphere a material of low density (gas) transfers heat to a highly dense material (land or water). I therefore think it’s unfeasible

  213. Hi I just stumbled on to your page and i find it very interesting I found answers to problems that i have looking for quite awhile but now I have another —
    How can I keep moths off of the underside of a colorboand roof could i use metho or kero thank you

    • If anything, kero – the metho would evaporate too easily. But before you spray the kero on, try dissolving some naphthalene (mothballs) in it first – it should dissolve. This will give you a thin layer of naphthalene on the metal that should fix the problem

    • Bit hard to say without knowing what it is, but there is no substitute for air, and lot of it. Hang it outside in the shade somewhere and it should dissipate pretty quickly

  214. Hi
    How do you remove the hard build up of deodorant stains from a cotton tie dyed garment without removing the colour of the tie dye. I did a search on your site and nothing popped up.
    Thanking you.

    • If it’s the yellowing from aluminium based antipersperants, any acidic bathroom cleaner will work (Easy OFF BAM with sulphamic acid)

  215. Hi,
    Apologies if this has already been answered but I searched your site and couldn’t find any information. We use rainwater tank water to flush our toilets. One toilet, which has an integrated basin on top where you wash your hands with the water that is then used for the flush, has a continual brown tinge to the water in the bowl. The other does not (using the same tank water). We’ve tried a variety of liquid soaps and this doesn’t seem to make a difference. If you have any specific suggestions that would be great but I’m also interested in how to keep a toilet bowl relatively clean during a flush without using products like toilet duck etc or bleach type products. It seems citric acid can be quite powerful and wondered if you had any products that you could recommend for a: cleaning toilets in genera and b: keeping them clean? Thanks in advance! Heather

    • The brown tinge is iron. To remove it you’ll need hydrochloric aid. Harpic used to make a product that was thickened HCl but I don’t think it’s on the market anymore. The alternative is to scrub it with some wet and dry – that will work well. On an ongoing basis there is simply no alternative to the use of bleach to keep a toilet clean – the reason simply is that it is just so rich in the bacteria that promote biomass growth and iron staining

  216. Hello Dr Chemical,

    Can you recommend anything to use in wardrobes and drawers to protect clothes from clothes moths and silverfish? I want to avoid regular moth balls which contain naphthalene which I understand to be carcinogenic (please correct me if I am mistaken).


    • Naphthalene is no longer thought to be carcinogenic. But one alternative is oil of cloves – I’ve had people say it keeps moths away. Or vicks vaporub – apparently the menthol is a pest repellant

  217. With washing soda being such a good cleaner along with some shine and protect properties, why is it not recommended for use on car paint.

    • I wouldn’t use it on car paint as it might scratch it. There are no issues chemically, but it’s fairly gritty and might scratch it, which is why its good for cleaning dishes and saucepans

  218. Hi, I have some golf balls that were retrieved from muddy water so the little dimples are dirty. Tried cleaning with standard detergent and water but it wont come off; any tips on how to clean the muck off the golf balls? Thanks, Frankie

  219. Hello Dr Chemical,

    We have bamboo floating floors in all rooms bar the bathrooms and laundry, 14mm click system with polyurethane finish. Can you advise the best way to clean it – the recommended hardwood floor cleaner was heavily scented and gives my husband and I a headache. We know you should only use a damp cloth/mop. Thanks so much!

  220. This is a question, can’t locate question section, anyway, my question is is there anything that can clean opaque garden solar panels or are they bin able when they go like this. Cheers Joy Grant

  221. We have gloss paint spots on new tiles on our bathroom floor and the tiles are not the gloss type of tile do you have any solution for removing please.

    • If you have a heat gun, blast them with that and they will just flake off. Or maybe a hair dryer at a pinch. Or soak a rag with metho and soak it on the tiles for half an hour. Or use Ajax Powder Cleanser (or Bon Ami). Any of those should work

  222. Dear Dr Chemical,

    What is your opinion on this latest eco-cleaning product to hit the market? Too good to be true, or plausible?

    “ekoWorx has been scientifically formulated with water, salts and ‘electrochemistry’. In lab tests, it has been proven to suspend and remove dirt and grease whilst killing bacteria. When released into the environment, ekoWorx reacts with carbon dioxide in the air to become completely inert.” Dr Leigh Aldous, Chem Dept, UNSW.”

    • In the absence of any further information I’d put it in the “plausible” category. It appears to use ionic liquids – I know what these are but have never seen them used in a cleaning application before.

      But there is a contact name at UNSW so I’ll look into it further. It certainly looks very interesting.

  223. Hi there, I was hoping you could please suggest something to remove old dried sticky tape (not just the residue) stuck on a colorbond pergola. Thank you.

    • Get some hydrochloric acid from the hardware store. Follow safety instructions on label. Dilute 1 part in 3 (eg add 200mL acid to 400mL water) and tip onto marks. Leave them to soak for a few minutes and you’ll see them dissolve. Then just wash away with water. Repeat as necessary or increase concentration if required

  224. Hi, How do l remove hot wax stain from a mari high polished table ?
    It has left a pink coloured stain …… haven’t tried anything yet ,I’m frightened to make it worse…..I please help Dr Chemical..!!
    Thanks. Marianne

    • This one’s a bit above my pay grade I’m afraid. I would say that what has happened that the hot wax has stripped off the polish on top of the table and also stripped some of the natural oils out of the Marri. If it was my table, i’d find out what type of polish it was and just repolish it, in the hope that the natural oils would replenish the surface with time (which is reasonably likely). The alternative of course is restaining it, but I wouldn’t even know where to begin when it comes to matching woodstains. The paint desk at Bunnings may be able to help – they sometimes have people with quite a lot of knowledge in these areas. Or you might just have to contact a French Polisher

  225. dog urine stained a cream carpet (not wool). My daughter put soda water and bicarb soda on it and it dried hard. Next it was dampened and carpet cleaning powder applied. Stain still there and fibres stiff. What next, how to remove the stain?

    • First thing to do is remove the dried bicarb, and then next thing to do is remove the urine smell. Fortunately vinegar can do both. Tip some on until you see no more fizzing, then just blot dry. You ma need to rpt if you see and dried powder when it dries. When it’s all gone the vinegar will neutralize the urine smell by acidifying the amines. Then you could put some Vanish carpet powder on it to finish

  226. Hello, I spilt brasso on a unpainted brushwood ( paintable plastic textured to look like rough timber) garden storage box. I haven’t tried anything yet . what can you suggest to remove it? It’s been spilt a while now and looks like rust. Thanks

  227. Five years ago I had my wooden boards polished with a water based varnish. Over the last 6 months white marks are appearing on used and unused areas of the floor, I invited a floor polisher in to get some advice. I was told that the patches were separating from the floor, no known reason and that I would have to have the whole floor redone.

    I am in my 70’s, a pensioner and the furniture is immovable…other than paying thousands for a commercial mover to move it. Is it possible to fix these marks?

    You gave me the name of the Carpet man….he does not know anything regarding wooden floor problems….thank you for your valued time

    • If the floor polisher says that the patches are separating from the floor, then I’d be going back to the person that laid the varnish. This shouldn’t be happening after 5 years. If you get no joy there I’d be taking it up with ministry of fair trading (Dept Commerce). I’ve had some dealings with them in the past and found them helpful

  228. Last night I began stripping an old cedar chest with Citri-Strip QCG73801T Paint and Varnish Stripping Gel. Upon finishing up last night, I put everything I had used and/or had dirtied up (rags, scrapers, bottle of gel, etc.) in a plastic bag and brought it all inside including the cedar chest still with a residue of stripping gel on it. It says that it is safe for indoor use so I really didnt think anything of what I was doing. Now I’m at work this morning and I’m experiencing some minor difficulty with breathing. Also, I’m now worried about my dog being in the house experiencing some prolonged exposure to any harmful toxic chemicals. I will take everything back outside at lunch nevertheless, and my dog is in a kennel that is not in the same room as the cedar chest right now – but the house is small. Anyways, will he be okay being exposed to that for the next couple of hours?

    Thank you.

    • It’s not the Citristrip. The active ingredient is NMP which is completely safe (and odourless) – that’s why it’s used. The citrus smell is a natural extract from citric fruits (orange oil). It sounds like it may be some allergic reaction to something but I have no idea what it is.

  229. I so not have a comment I have a question…so please pass this on the Dr Chemical. Five years ago I had my boards polished with a water based polish. Over the last 6 months white marks are appearing on used and unused areas of the floor, I invited a floor polisher in to get some advice. I was told that the patches were separating from the floor, no known reason and that I would have to have the whole floor redone,

    I am in my 70’s, a pensioner and the furniture is immovable…other than paying thousands for a commercial mover to move it. Is it possible to fix these marks?

    Or would it be possible to purchase a normal home polishing machine and just put wax on the floor as it peels off? I can tell you I am beside myself and am in great need of assistance. Thank you for your valued time

    • That advice doesn’t sound right. I’d be getting a 2nd opinion if I were you. I’m not sure where you are, but if you are in Perth call Duncan Beatty at Clean Underfoot on 0418 916245. Alternatively Bunnings hire floor polishers, and they normally have people who can give good advice

  230. Hi Dr Chemical
    My dog urinates on my plants in the garden and is killing them of, is there anything i can do to resolve this problem, kind regards Geoff

    • Get some jars of Vicks Vaporub, take the lids off, and sit them near the plants. I’m told it works well, as the menthol fumes mask the marking odours that the dogs are looking for.

  231. i have a pure wool carpet. While taking out Christmas tree the water in bottom tipped out. i sprinkled bi carb over & cleaned with warm water, vinegar, detergent & it didnt work. I then called a carpet cleaner who used something that he said wasnt vinegar but smelt the same. Then steamed cleaned it. It looked as though the stain was gone. After awhile as the carpet dried the stain was back.
    can you help

  232. What a wonderful site! I have an indoor teak table oiled with a mix of linseed and turps which has gone sticky in high humidity. What do you suggest I use to strip it off that won’t damage the wood?

    • Linseed oil oxidises in air and polymerises with time. If anything will work, it’s turps. Failing that try “Easy Cleanup” from Bunnings, or acetone

    • Buy some washing soda (not baking or bicarb) from the cleaning aisle in the supermarket, make it into a paste with water and a scourer and it will work a treat

  233. Usually when the guys working in the factory of the business that I work for come into the office area they leave their work boots at the door. One of them forgot to do that and has left oil footprints on what I think is synthetic carpet. What can we use to remove the footprints? It looks a bit like a crime scene at the moment.

    • It’s a bit tricky as leather is pretty fragile. Wet a rag with metho and soak it against the mould. Eventually it’ll kill the mould and it’ll be able to be brushed away but it might take a while

  234. I oversprayed a spring controlled moveable arm on a piece of equipment at work and now the arm won’t stay in place where I put it. Is there anything I can do to counter the overuse of spraying too much WD40 on the spring mechanism?

    • If that’s what it is, any acid will get it off. Have a look at the labels on your bathroom cleaning products. Get some Ajax Spray & Wipe Bathroom if you don’t have any

    • Bit tricky as I’m not sure what it is. Try Preen Oxy-Action prewash. Spray it on and leave it – it might take a while but it should do the job. You may have to do it a few times

  235. Hi
    Excellent show on Curtin, thankyou. Two questions. Firstly how to remove rust stains in the bottom of a swimming pool. Made by my daughters hair grips!
    Second question, how to remove engine oil stains from pavers.

    • If you have emptied the pool you can get th rust off with hydrochloric acid (1 part in 3). wear gloves and safety glasses. To get oil stains off pavers sprinkle some caustic soda flakes on the area. Wet down with a minimum amount of water then use a stiff broom to scrub it in. Then hose off with a HP cleaner. But it won’t get it all off as pavers are porous

  236. Hi Mark, Can you please advise the best way to remove a black scuff mark from a white carpet. this carpet is new and never been shampooed!

  237. Hi , what can I use on my fibreglass pool to remove the dullness of gunge build up above the waterline !! Have tried liquid Jif Cream cleaner but to no avail !! Would like it cleaned back to its original shiny surface if possible , your program on curtain fm is not worth missing as it is superb !!

    • I’d try oven cleaner on it – spray on, allow 30 sec or for it to react, then wipe off. If it’s organic buildup it’ll work, but if it’s inorganic it won’t. In that case try an acidic bathroom cleaner (such as Easy Off with sulphamic acid as the active ingredient)

  238. Dr Chemical
    How do I remove red dust stains from a vehicle of the type people get from driving in the north of the state. I assume it is the iron in the dust which is the problem.
    The worst surfaces are galvanised steel, aluminum and plastic body parts.

    Regards Steve

    • The red dust is due to either clay or iron. Where you can get to it squirt oven cleaner onto it – that will neutralise the acidity that the red dust has (if it contains iron) that causes rust, and will make it easy to wipe off

  239. Hi I have just about to open a cafe and am stocking up on cleaning chemicals. When I am looking at a degreaser for the floor it says it can’t be used on polished or sealed floors. What exactly does that mean as not very clear on the internet. Also a few of the stainless steel appliances have what looks like run marks on them, how has this happened and can I get rid of them.

    Thank you

    • The best polish for stainless steel is Brasso. With a bit of elbow grease it’ll get the run marks off. Best floor cleaner is ammonia. 1 part in 50 generally, or higher if the floor is dirtier or greasier

  240. Hi Dr Chemical,

    Is there anything I can use to clean dog urine from carpet? Also is there something I can use to deter my dog from doing it again?
    Kind Regards

  241. Please could you help with the removal of oil stains on a cotton top and also the best way to clean grout in-between the tiles on a 14 year floor. Have tried a few tile and grout cleaners with limited success.
    Thanks a million
    Regards Josie

    • For oil stains use an oven cleaner. Spray it on, work in with your finger and rinse. Use AJAX Professional Bathroom cleaner for the grout

  242. Hi I have a chair that is covered in100 per cent polyester luxasuede,I was advised by the retailer to use there cleaner but it has left water marks, is there any thing that can be done to get rid of the marks.

    • That’s a tough one – water marks are very hard to get off suede. Someone asked a question on my blog a few weeks ago, and someone posted in with a solution, but I can’t remember what it was, but if you browse the questions you should find it

  243. hi dr chemical have been listening to you on Jennys show can you please tell me how ican get white coffee stains off concrete in the garage I have a disability daughter he smokes in garage and falls asleep and knocks her coffee all the time I need something as I have to hand this house over in a week hope you can help me thank you very much

  244. Could you please tell me how I can remove some of the glue that is used to join bamboo flooring that has splashed and dried on vinyl lino, also wooden cupboards.
    This happened over a year ago and I have tried every thing I can think of to clean the dried stuff off with no success.

    • Acetone will do it, but do a spot test first to see that it isn’t damaging the surfaces. If it is, try metho – soak a rag and sit it on the glue for an hour or so – that should shift it

  245. Hi how do I remove hard solid antiperspirant build up from business shirts. I’ve tried baking soda vinegar hydrogen peroxide but no combination seems to work. I need some thing that will dissolve the build up which I know is the aluminium in the antiperspirant. Please tell me something thT will finally work.

    • Baking soda and vinegar won’t clean anything, as you’ve no doubt discovered. I’d like to know what conc peroxide you used, as it is not an over-the-counter chemical. I’d try an acid first – get some Easy Off bathroom cleaner (forget the actual product name) with Sulfamic Acid (listed on the label). Squirt that on and see if it does anything. If that doesn’t work, try an enzyme cleaner – Biozet liquid laundry detergent. Rub in with your fingers – allow some time – enzymes have a slow mechanism of operation. Rinse and repeat. Failing that, try an oxidising prewash (Preen OxyAction). Spray it on then leave it. last resort, a premium brand whitening toothpaste (that contains peroxide). Rub it in, and rinse and rpt if necessary.