Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Muriatic or oxalic acid as wood bleach?
Q. Someone had installed new windows in this old stone bank and left it sitting for 3 to 5 years. Now the new owner wants me to try to do something to bring it back to new. Well, like I said, there is a black ring around a bleached area. You can see where the sweat came of the window and sat on the 3/4 stained and poly oak. The sills are about 24 inches deep. I thought about sanding with 80 grit but I think I would still have the stain. Thanks.
Richard Gaudette2006
March 4, 2011
Hi, Richard.
That is not within my actual personal experience, but I have heard that "oxalic acid", also called wood bleach ⇦this on eBay or Amazon [affil links] , can solve problems of this sort. I suppose it's worth a try. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. Years ago, when my family moved into a lovely but somewhat rundown home, my father and I cleaned the oak woodwork with what he called muriatic acid.
Do you think muriatic acid is appropriate for this kind of work?
- Lawrence, Kansas
April 22, 2010
April 23, 2010
A. Hi, Corinne. It doesn't sound appropriate to me. It was, as you say, years ago and your memory may be playing a small trick. I do believe that oxalic acid is wood bleach ⇦this on eBay or Amazon [affil links] though.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
RFQ: I am looking for someone who sells Oxalic Acid in the Boise/Treasure Valley area. And help would work. I have called several places and no one so far. Thank you
John H [last name deleted for privacy by Editor]- boise, Idaho
July 22, 2013
Ed. note: Sorry, this RFQ is old & outdated, so contact info is no longer available. However, if you feel that something technical should be said in reply, please post it; no public commercial suggestions please ( huh? why?)
A. Being a professional finisher for thirty years, spanning this country and Greece, I was taught the finishing techniques that spanned a century. I have used muriatic acid many times, but safety guidelines are paramount. This is a volatile and dangerous material so take care. (See next paragraph: MSDS). The brand and company who make the solvent will send you directions for use and the safety data -- read it all before handling this material.
I am here to say that muriatic acid
⇦this on
eBay or
Amazon [affil links] is a perfect wood bleach to reset the surface and cuticle of the wood to receive your color and finish treatments. Use this material outside and, if inside, must have a professional evacuation system for air because it can ignite inside an enclosed space as well as being a safety hazard to people and animals. Wear rubber gloves
⇦this on
eBay or
Amazon [affil links] , charcoal respirator
⇦this on
eBay
or
Amazon [affil links]
and waterproof suit when handling this material. Also, contact tech support for the brand of material you buy for that specific product of directions/usage and MSDS (Material Safety Data Sheet.)
When bleaching of wood is done, clean with lime and water to neutralize the remaining acid residual.
Of course, Cabot (who are the makers of Valspar), make two products that can help you: "Wood Cleaner" ⇦ this on
eBay
[affil links]
and "Wood Brightener" ⇦ this on
eBay or
Amazon [affil links]
.
Good luck.
- Traverse City, Michigan
March 14, 2015
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