Oxalic Acid (Advice Needed)

[Willbury]

Hello,

I'm looking for some advice on how to properly use oxalic acid to remove some small blue stains caused by iron. I've gone out and bought a container of Oxalic Acid crystals and would like to know how to properly mix it, and apply it to the spots. I also understand that I should try and make sure there isn't residue left after the process, what is the best way to remove the residue?

It seems like quite a few of you use this stuff, but I can't find much info on the steps to follow.

Any advice would be greatly appreciated.

Thanks!

Will

[Northmount]

I mixed about 1/2 tsp in a cup of water. Swabbed the leather with a sponge full. You could see the change immediately. Then immediately rinsed it off with running water and wiped / blotted it off. So I think this was a fairly strong solution. You could try 1/2 this to start with.

The whole surface needs to be treated, not good for spot cleaning. Really does a great job evening out the surface color.

CTG

[gringobill]

Hello,

I'm looking for some advice on how to properly use oxalic acid to remove some small blue stains caused by iron. I've gone out and bought a container of Oxalic Acid crystals and would like to know how to properly mix it, and apply it to the spots. I also understand that I should try and make sure there isn't residue left after the process, what is the best way to remove the residue?

It seems like quite a few of you use this stuff, but I can't find much info on the steps to follow.

Any advice would be greatly appreciated.

Thanks!

Will

I use woodbleach I got at Home Depot, which is oxcalic acid crystals. I mix it up in a quart jar and keep it on my bench because I seem to need it pretty often. I think I have been putting about 1/4 cup of the crystals in a quart of warm water when I mix it up. That may be way too strong? it sure works. Sometimes I use a sheepskin pad and apply sparingly to the whole piece and sometimes I use a wool dauber to apply it to small spots, I mean tiny spots, like pin point spots. Like I said my mixture may be too strong. I have been using it for many years but have never seen a definitive formula for the right strength. I think the less you can get by with the better off you will be. Sometimes the stuff has a chemical reaction with other finishing products, like oil, and can leave a slighty darker area. I have never taken the step of washing the piece off with plain water and that may be a good idea. I had never heard of doing that until I just read it here. Like I said, I apply it pretty sparingly, just enough to remove a spot and stop.

Bill

[Northmount]

There are 96 items in the forums when you do a search for oxalic. Do a search and enjoy!

One of the ones I read a while ago is Here

In place of oxalic acid, you can use vinegar or lemon juice.

Good luck with your clean up.

CTG

EDIT: From a book "General Leathercraft" by Raymond Cherry, 4th Edition © 1955, comments about cleaning leather after tooling and preparing for dye and finish.

"Dissolve 1 tsp oxalic acid crystals in 1 pint of water to make a cleaning solution. Apply the solution with a cellulose sponge. Let the Leather dry completely."

He doesn't say anything about rinsing the acid off after application. It's a pretty weak acid, so the leather will neutralize it anyhow if you don't want to rinse it.

By the way, this is an excellent book for beginners. I used it in 1960 when I was starting leathercraft. I did a web search for it a while ago. ABEBooks.com and Amazon.com had copies available for a very reasonable price.

Edited February 28, 2012 by northmount

[Willbury]

Thanks for all the advice, I'll give this a go!