Removing rust mark on wet room floor

weapon of choice from scotchbrite pad steel pan scourer magic eraser

together with potion of choice from white vinegar viakal whink stain remover (weak HF acid)

take it gently and stat in inconspicuous corner ...

I am amazed that it is possible to buy a product containing hydrofluoric acid (I think that glass etching kits contain something else), but I couldn't find out what the strength is. I'd wear nitrile gloves at least while applying it, and keep any liquid well away from glass!

I think that's vinyl flooring?

I've been looking into citric acid based chelating agents recently for derusting metal parts - eg a mixture of citric acid and sodium bicarbonate can be made up to be a pH neutral buffer so as to not attack the metal, but still chelate the rust. Somebody did some trials and it worked well:

So if you have some citric acid you could try it on the rusty stain. Being vinyl the citric won't attack it so doesn't need the buffer.

Theo

Definitely need Eye and Skin protection and keep your mouth closed.

Rub it over with a mixture of cut lemon and elbow grease.

Under 2.3% according to MSDS

Good plan.

In message snipped-for-privacy@q957.zbmc.eu>, Chris Green snipped-for-privacy@isbd.net writes

I did this recently - lavvy brush holder was the culprit. . Light scour with steel wool and bleach.

Brian

Thanks for the video. I was aware of Evaporust and per Ed China bath of the stuff to de-rust a chassis that some calculated at £20,000 worth of Evaporust.

But I wasn't aware how effective the combination of citric acid and a buffer was in comparison.

There's a chap* who apparently has has easy access to slip unofficial samples through a uni's mass spectrometers, he does youtube shorts analysing everything from fast food and nicotine gum, to chemicals such as Evaporust, he says the chelating ingredient is triethanolamine phosphate ...

Yes, I saw that video and worked out how much it cost. That started me on a little detour about low cost alternative solutions. Various folks suggest citric based derusting, but they don't address the acidity. Some use EDTA, which is still a bit annoying to get hold of. So I started pondering about buffer solutions using household chemicals... thought about bicarb, searched and found that video demonstrating it works very well.

I've also been looking at rust proofing solutions - the current heavily advertised product is 'Lanoguard', which is lanolin in a solvent. Lanolin seems to be useful as an oil that polymerises into a coating and can be regularly reapplied. It turns out there are a variety of third party lanolin based products for a fraction of the price. One of the 'homebrew' videos is pure lanolin plus a proprietary 'thinner', which turns out to be D100 solvent ('C13-C15 paraffins and naphthenes'), so I reckon lanolin plus white spirit ('Hydrocarbons, C9-C12, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) 100%') would be worth a try. Although supposedly lanoguard doesn't attack plastics which white spirit might - maybe their solvent is better.

Anyhow, this is a job for the summer...

Theo

Yes:

Also included are:

which makes it look like an acid-salt buffer solution. I think the acid may be citric, but I couldn't tell for sure. I think the triethanolamine may be the carrier for the chelating agents, rather than the active ingredient itself.

Theo

It's available from Amazon, and isn't too expensive. e.g.

Theo

Bleach for rust IS NOT recommended!

Just Google "Bleach and Rust" to bring up many hits for the reason not to use it.

I use "Cosmoloid H80" -- a "microcrystalline wax", whatever that may be.

This can be applied to hot metal, or dissolved in white spirit/Stoddard solvent/thinner/whatever.

I use "Shellsol T" which is an alkane solvent free of aromatics (doesn't smell, plus less toxic), at 20 grams Cosmoloid to one liter -- a very little Cosmoloid goes a long way. Treated metal is not greasy or waxy to the touch.

Thomas Prufer

Thanks. I have been using electrolysis to remove rust but yours seems to be a quicker & easier solution (no pun intended).

Yes, I was wondering if there was a generic purer alkane solvent like Shellsol. Trouble is that it's only sold in art supply places at about £18 a litre, which makes it quite pricey. Bulk price in 1000 litres is about £1.40 a litre so that's quite some markup.

There's also 'turpentine substitute' which is fairly cheap, but that appears to be just a less pure version of white spirit.

Theo