oxalic acid help please

Duncan · Post by **Duncan** » Thu Mar 15, 2007 10:15 am

I know this subject has been on the forum before but i have forgotton all the info!!:oops:
Doe's anyone know any source to obtain oxalic acid . I have been to several chemists but they can't sell me any as its a poison . I assured them i wasn't trying to kill my wife but this didn't seem to matter much, still no!! ( fancy being bleached to death , wot a way to go !! )
Anyway when we lived in wales i could buy it in a ready made form called Liberon wood bleacher although a bit expensive, but in Cornwall i can't seem to even find that. Maybe Ed has a source being in this neck of the woods.

Garry R · Post by **Garry R** » Thu Mar 15, 2007 11:49 am

Is this the stuff?

http://www.heritage-homeandgarden.co.uk ... ts_id=2789

Post by Ed » Thu Mar 15, 2007 12:02 pm

Fraid I don't know.....

when I used to buy chemicals for weird and wonderful photographic techniques, I used to have to sign a 'poisons' book. I might well even have some oxalic acid, but that was long ago in London.

I don't like using wood bleaches much at all and as a rule prefer a black patch to a grey one which seems to always be what you are left with.

I have used Rustins 2 part bleach, but I suspect this works using strong base such as Hydrogen Peroxide rather than an acid.....But again not to much great sucsess.

Have also used Netrol wood cleaner, which does brighten some wood, but does not really move black stains much.

If I was looking for Liberon Products, I would normally look in Robbins Timber in Bristol.

there is also another range of wood polishes and cleaners called something like MG or M&G......will have to look downstairs. Neil put me onto these and again I have had some limited sucsess. These are available in quite a few places in southwest, including Exeter and Oakhampton, but sure they are also further west.

I will find name when I next go into the workshop (most probably 2008 at current rate).

cheers

eib

Garry R · Post by **Garry R** » Thu Mar 15, 2007 1:42 pm

I found on Gannet that it didn't work for me hence I have black bits. Chris said he used some on his Albacore and certainly it looks great - perhaps I am just not doing it properly. Is mahogany a problem?

Duncan · Post by **Duncan** » Thu Mar 15, 2007 2:57 pm

I have found on mahogany it actually works best . Black stains just disappear. My enterprise was almost black all over and it came up like new. It does being acid open the grain right up tho so has to be sanded smooth again.

Post by Ed » Thu Mar 15, 2007 5:14 pm

There has been so much talk about using bleach.....well Oxalic acid.

That I think someone should write a master class on the subject (with lots of photos) and we can have it up on line in the 'hints'n'tips' section.

Just need to do it quick before the Forum gets blocked with posts about why we shouldn't go near Oxalic acid without a head-to-toe condom on.

cheers

eib

Garry R · Post by **Garry R** » Thu Mar 15, 2007 5:23 pm

Condoms.... well certainly with my lack of success with the stuff I feel a bit of a p***k!!!! Seriously though maybe I didn't have the right concentration/time etc to get it to work and I'm always worried that it's eating away at the wood if you don't wash it all off and it starts to work again if it gets damp.

Post by Ed » Thu Mar 15, 2007 7:45 pm

well if you are worried about it starting to work again, it may be worthwhile washing it down with some simple Alkali, which will neutralise the acid. But personally I think that just washing in water should do it.

In fact I think a jolly good wash with lots of water and a good scrub with some soap nearly always seems to help. I never used to wash down unvarnished boats as I was worried about the boat getting too damp. But recently I have just worked on principle that it would need a while to dry....and then given it a good wash. I have been amazed by how much difference and good this does. in fact I often wonder if the improvement comes mainly from the 'netrol' or just from the scrubbing. I suspect sometimes it is just the good wash that does the trick.

cheers

eib

jonathanR · Post by **jonathanR** » Thu Mar 15, 2007 8:33 pm

This stuff is or was a popular poison in days gone by and saw off many a spouse or ex!! You need to know a chemist/pharmacist who can vouch for your good character. I was refused supply by high street pharmacies and one insisted I identify myself even though they were not going to supply me. I eventually found a pharmacist for whom I had done some work a few years prior and he was satisfied with my credentials and purpose of purchase. He spplied a kilo of crystals.

Good luck

alan williams · Post by **alan williams** » Thu Mar 15, 2007 11:10 pm

See previous post for comments. This is a licenced substance.
Cheers al

Ianphot · Post by **Ianphot** » Fri Mar 16, 2007 10:22 am

I bought mine in France - was on the Bricolage (DIY) shelves among the wood treatments and was fairly inexpensive. Are the French less H&S sensitive?
Worked well on my GP though the French instructions were not that easy to follow - the correct strength and plenty of time seemed to work. I found it worked better on solid wood than ply decking. Maybe I should import some next time I am over - customs explanations might be interesting!

Garry R · Post by **Garry R** » Fri Mar 16, 2007 11:10 am

What IS the correct strength as that seems to be critical?

JohnK · Post by **JohnK** » Fri Mar 16, 2007 2:23 pm

Maybe I've just been lucky, but for the last few years I've found a good blast with a hot air gun seems to clear most of the black, and careful application (ie using a small watercolour brush to hit the line of the grain) of Domestos at various dilutions does the rest. Seeing that Mike Golding needs new mast, I'd better use the Ecover equivalent next time.

John

Ianphot · Post by **Ianphot** » Fri Mar 16, 2007 3:05 pm

Good information and supplier - http://www.agwoodcare.co.uk/show_produc ... QgodLkHYcQ

Although it is an acid it is not in the same class as Nitric etc. Washing off with plenty of water is enough for our purposes but make sure you avoid inhaling the vapour. Gloves, face mask and protective eyewear should be used when mixing and applying.

johnebailey · Post by **johnebailey** » Fri Mar 16, 2007 4:58 pm

I have received numerous requests on this topic but can't offer much advice.It is available at most Chandlers,Blakes market it I believe John