Search results for query: oxalic acid

Great advice re. the hot water, thanks. Do you know a good ratio for crystals to water? I have heard 8 to 1, does that sound about right?

...is a strange thing that this is fairly well known in arboreal circles but nearly unknown in the world of cutty & choppy up wood. edit oh and as @Peter Sefton said above by bleaching, I didn't mean house bleach but oxalic acid as used to bleach wood to lighten/draw out the colour from stains etc

I would give it a light sanding first with some 240grit sandpaper then apply a solution of oxalic acid and scrub it into the wood with a nylon scourer then leave overnight, wash off with plenty of fresh water and allow to dry. You can get oxalic acid in crystal form in small quantities very...

I had an oak draining board in a utility room which inevitably got black stains from (tannic acid / iron) wet iron objects. I'd heard of the oxalic acid fix so ebayed a bucket of oxalic crystals. Worked perfectly. Never tried it on anything else.

I've just checked and Bar Keepers Friend is mainly citric acid. I've also got some of this STARWAX FABULOUS Sorrel Salt - 400g - Ideal for Bleaching Wood and Eliminating Rust Stains which is oxalic acid. As stated above, it also works very well.

If it has all been coated with Osmo Polyx as you suggest (or similar finish) then I very much doubt that oxalic acid will do a lot. I build in oak quite a bit and oxalic in my experience has some effect on bare wood but is less of a magic cure for stains than people think. I would select an...

...veneered, first try some weak household bleach wash over the panel to see if it helps-my guess is it won't. Then on a fresh panel try oxalic acid or peroxide to see if that removes it. As Droogs says I would think the veneer has something in it and the moisture is awakening it, I am sure you...

Not come across oxalic acid before. Will that work on other woods like teak or sapele or is it purely suitable for oak?

I should have mentioned that barkeepers friend contains oxalic acid which is why it’s a user friendly way to get hold of it, from any decent hardware shop

I use oxalic on untreated oak. I buy it in 10kg tubs in powder form. It will require a miracle to lighten your tanalised shiplap without sanding down past the impregnated surface. Oxalic acid will not do it.

...One also gets this blue black gunge on the chipbreaker. Fine wire wool and metal polish , like Autosol will deal with the problem. Sometimes the blue stain gets all over the timber. A dilute solution of Oxalic acid will clean the timber. Neutralize or wash afterwards. David Charlesworth

...bad it has become and also what it was last coated with. If an oil finish then a pressure washer should do followed by scrubbing with an oxalic acid deck cleaner to help bring back the wood colour. Sanding should be a last resort if it's really manky. Sanding will also take the coating off...

Well I've tried some bar keepers friend which has a small amount of Oxalic acid in and it's made a good difference on the wood. SO I've ordered some O Acid and will try it properly at the weekend. Photos will follow - phone not working at mo!

Too rustic in colour or texture? Before you give in you could have a go with some Oxalic acid (wood whitener) to bleach it back. Cheers Andy

...brownish tide marks which I know are tannin stains, I thought it wouldn't be too much bother to shift them. So far, I've had a go with oxalic acid which has kindof worked but there's still noticeable marks. I was wondering whether would putting them through a planer work? As in, would it...

I’ve ordered some oxalic acid and going to try a test step this weekend, will let you know how it goes. Pretty much my last resort, after that I’m just going to finish it with one or two coats of the osmo tint did you use any epoxy resin for cracks? I’m not sure whether to repair a couple of...

...There is no need to put a finish on, although a little oil or wax might be good for looks. Side note: you can remove tannin stains with oxalic acid. I’ve done this in the past, and it is nothing short of magical. Try searching YouTube for videos. Oxalic acid is readily available online and...

...As many suggested, the problem was a bit of a lost cause and the bottom line was, the stains could not practically be shifted. I tried: Oxalic Acid, Wood Bleach, Hydrogen Peroxide, White Vinegar, Lots and lots of elbow grease with 80 grit. In the end we took the pragmatic approach and...

...we are aiming for the legs to look like the top so embracing the dark patches would be a very last resort. My gut feeling is that it is the dye but I will try the oxalic acid and also hydrogen peroxide and see what happens. 12 months in a sunny spot would be wishful thinking with the UK weather!

...mould generally comes back blacker after bleach..... which is why you get poroper mould and mildew treatments.... i personally would use oxalic acid to treat it, it should kill off the bacteria and restore the oroginal colour. Then do a good job of redecorating the window to help seal it...