Official Luthiers Forum!

Clay S.

I am not sure how much is in there, i have heard you should not get denatured if it is over 5% methyl. There are some other additives that are toxic as well. How much and to what degree? I cannot say 100%. I do know this, i prefer to have something that is food grade to work with. If i can eat it, it cant be totally bad for you. In this case Alcohol can be bad for you itself but it is still food grade so the safest way to use alcohol is without additives. Does that mean it is better? Probably not. Just my opinion on using Food Grade alcohol vs Denatured.

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久保
美智え

Score! I'm in Silver Spring, Md. this weekend visiting my wife' father. Went to the liqueur store and found 190 proof grain alcohol! I guess it won't be there much longer....

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

Has anyone ever used this 200 proof chemistry grade alcohol for French polish? Would it be superior to Everclear?

I was under the assumption that once you expose this high of a percentage of alcohol to the air. It will down the percentage between 96-98%

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久保
美智え

I have been told before, too, that 100% (200 proof) ethanol will absorb water from the air and become about 95%. This makes sense, because ethanol and water form an azeotrope at 95% ethanol. This is a liquid chemical combination that behaves as if it were a single compound when distilled. So, with a simple distillation, you cannot get pure ethanol, but only 190 proof. I think that if the 200 proof stayed 200 proof during the mixing up and storage of the shellac for French polish, applying it to wood could extract all of the normal residual water from the wood, which would be temporary and I do not know if harmful.

There are many different manufacturers of denatured alcohol and their formulations vary all over the map. (Literally, as different countries have differing regulations.) I looked at several different MSDS sheets and the ones I saw varied from about five to to 50 percent methyl alcohol. One thing they all agreed on was that methyl alcohol is quite toxic if ingested, and overexposure due to skin contact or inhaling the vapors can produce the same results as ingesting it.

I'm pretty sure that a few exposures or careful FP sessions with protective gloves and appropriate ventilation would be safe enough. At least I hope so that's -- how I started out! But what worries me is the potential risk from chronic exposure. Apparently the effects from accumulated exposure can eventually produce serious health problems: dizziness, fatigue, tremors, permanent central nervous system changes, blindness, pancreatic damage and death.

Of course, old age can produce the same symptoms.

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D..