Expert: Henry Boyter - 11/8/2002

Question
Is there a chemical difference between Isopropyl and Denatured Alcohol. (Yes, I know that you don't drink either one.) Can they be used interchangeably?

I use 91% Isopropyl with my air brush to thin some model paints and to clean the brush after use. On the woodworking side of my hobbies, one of the glues I use (Gorilla Glue)suggests the use of "Denatured Alchol" to clean up uncured glue squeeze-out.

Thanks for listening,
 T.A.Busch

Answer
Denatured alcohol is ethanol (drinking alcohol or grain)that has been contaminated so you can't drink it.  They are not the same thing.  They can be interchanged in most cases but not all.  For glue, isopropyl probably will not work as easily as ethanol, but may only take more scrubbing.  BUT remember, 91% isopropyl is 9% water, while denatured alcohol is <0.1% water.  The glue may not like the water.  Only trial and error will tell.