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Dichromate staining and safety

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dickm

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I've regularly used pot dichromate to colour oak and cherry, but my daughter, who is an industrial chemist, has come up with dire warnings about its hazardous nature. She claims that since the chromium in this is "in the hexavalent form" (which rings a few bells from O-level chemistry) it is a potent carcinogen. Therefore not something to be sanding after application.
Do any Health and Safety experts out there have comments? It produces such a good colour on oak that I'd be loth to stop using it, but....
 

Chris Knight

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Dick,

Potassium Dichromate is well known as a toxic substance as noted here http://www.camd.lsu.edu/msds/p/potassium_dichromate.htm

Having said that, I believe that with proper protective gear it should be fine.

You might try alternatives. Other chemical stains that work on the woods you mention include lye (caustic soda for cherry) ammonia for oak and nitric acid for both. All these have their own dangers but again, proper usage should be fine.
 

dickm

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waterhead37":1ggv0zc3 said:
Dick,

You might try alternatives. Other chemical stains that work on the woods you mention include lye (caustic soda for cherry) ammonia for oak and nitric acid for both. All these have their own dangers but again, proper usage should be fine.
Thanks for the url - I'll have a look and scare myself.
Have tried most of your other suggestions, and none gives quite the colour that dichromate does.
And, of course, dichromate is still used in slide film processing as a quite concentrated solution!, with relatively gentle safety instructions.
It's mainly post application sanding that seems a bit dodgy to me, though I always wear a powered resp for this.
 
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