Alcohol and Alcohol

Denatured Alcohol vs. Isopropanol

Stan Campbell

>I found this on the web, but it doesn't say anything about what will happen if you mix the 2.

Denatured Alcohol is ethyl alcohol, or ethanol, containing traces of benzene. While ethenol, in it's natural form, is a source of combustible fuel, it contains trace amounts of water making it less efficient for burning than in it's denatured form. Introducing Benzene during the distillation process drives out the water contained in ethanol creating a very pure and potent fuel source - denatured alcohol.

NOTE: Ethanol is the alcohol consumed in alcoholic beverages. However, once denatured, ethanol becomes toxic and can cause blindness or death if consumed.

Rubbing Alcohol is isopropanol. It has a completely different molecular structure than ethanol and often contains up to 30% water. Though it is flamible it is a poor choice for fuel.

Stan

Columbus,OH

Re: Alcohol and Alcohol

JL work

>Denatured alcohol typically does not contain benzene as a matter of course. It typically contains Methyl Isobutyl Ketone, Methanol and sometimes Ethyl Acetate and a trace of kerosene. They used to use benzene to "break" the azeotrope so the ethanol would distill over without the water. They stopped using it a while ago due to the environmental concerns.

You can get isopropanol in better grades than the rubbing alcohol grades. Isopropanol will mix thoroughly with ethanol.

We get highly technical here......

Jesper, Denmark

>I am assuming we are talking about using alcohol to soak bowls prior to drying.

The function of the alcohol is most likely that it dilutes the water in the wood, and when it evaporates, the azeotrope formed between the water and the alcohol means that the evaporation happens in a fixed ratio between the water and the alcohol. This function means that there is more water evaporating than alcohol as the water ratio in the vapor space is fixed by the azeotrope formed.

Assuming this is the right function, it does not matter much which type of alcohol is used (except methanol, as it does not azeotrope,) as they all azeotrope with water and have more water in the vapor form than you would expect from their boiling points or their relative composition in the liquid phase in the wood.

Soaking the wood in the alcohol will most likely make the water/alcohol mixture in the wood equilibrate, so that the mixture is the same in the liquid surrounding the wood and the liquid in the wood itself. as you remove the wood from the bath, the evaporation will favor the water, hence drying will be faster.

I have no clue why the wood would not crack as a result of this, but the drying ( = removal of water) function makes sense.

Happy Thanksgiving