I read in Shop Drawings for Greene and Greene Furniture, by Robert Lang, the original recipe the brothers used for staining their mahogany furniture. This recipe begins with using Potassium Dichromate. I have found a source for this chemcial and also have downloaded from the internet the MSDS for it. I would love to try this recipe.
I have worked extensively with fuming and have the appropriate full face mask and multi vapor cartridges and proper gloves, having researched this. I would love to try the potassium dichromate.
I am a hobbyist woodworker. The MSDS on this chemical is scary. I am looking for an opinion on the use of this chemical. If I use the proper safety equipment am ok in trying this or is it just not worth the risk?
Replies
At the risk of jumping in ahead of Peter, I searched the Knots site for some information on potassium dichromate because I recalled that there had been posts on the subject of its toxicity. There were several posts along the lines of this one:
You do know that dichromate is highly toxic and carcinogenic? The word HIGHLY is stressed. I won't have it in my shop and certainly would never allow it in the house. Look up the materials safety data sheet. Toxic threshold level: 0,05 milligrams/cubic meter. One ounce will contaminate 56,000 cubic meters. Cyanide is candy in comparison. Potassium cyanide toxicity threshold is only 5 milligrams per cubic meter. 100 times less toxic than dichromate. Cyanide is only rated as a class 3 hazard. Dichromate is class 4. Both are absorbed directly through the skin. http://www.jtbaker.com/msds/englishhtml/p5719.htm Anybody who sells this for woodworking purposes is highly misinformed. 100 years ago, they didn't know any better. Now they do.
It would seem that your concerns have a definite basis in fact.
Another post mentioned that Jeff Jewitt has a non toxic method of creating the look created by potassium dichromate.
John White
Hi John,
No risk of jumping ahead as I would say the same thing.
There is a romantic notion that these old recipes are good. I always drive home the point with students that these were the chemicals they had.
The dangers were not known as we know them now
I fully concur; stay away from it.
Speaking of old recipes; have you ever seen a "fire gilt" object such as bronze clock? They couldn't understand at the time why the gilders were dying off. The hot mercury in the process was just a wee bit toxic.
Happy New Year.
Peter
Not only is potassium dichromate directly harmful to your health, the chromium in it is a very potent environmental pollutant.
-Steve
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