Originally Posted by
cmfx_2
I can't find info on the web about a comparison of the two. Would just like to know if the Methyl Hydrate is an acceptable replacement for denatured alcohol?
A compact organic chemistry primer: Organic chemistry is the chemistry of carbon compounds. The simplest is methane. That has one carbon and four hydrogens. Ethane has two carbons and 6 hydrogens. And Propane has three carbons and 8 hydrogens.
CH4, C2H6, or C3H8
If we sneak in an oxygen between a carbon and one of its hydrogens, it becames an alcohol. The key "group" of an alcohol is that it has a -OH somewhere rather than an -H. You can make alcohols from the above compounds* to get methanol (wood alcohol, also called methyl hydrate), ethanol (grain alcohol, which is the stuff in white lightning and vodka and beer), and propanol. Since in propanol the carbons are bonded together in a chain (C1 to C2, and C2 to C3), there is a difference between propanols with the -OH on the center carbon, or on one end or another. If the -OH is in the center, its called isopropanol. Rubbing alcohol is made from either or isopropanol or ethyl alcohol mixed with bitterants and toxins to the latter to preclude use as a beverage. BTW, if methyl alcohol is added as the toxin to ethyl alcohol, its called methylated spirits. So methanol, ethanol, and propanol (also called methyl, ethyl, or propyl alcohol).
CH3OH, C2H5OH, C3H7OH
Your question centers on the physical chemistry of these alcohols, to wit, "Can I clean my brake discs with any of these?". Unless you drink them, all of these have pretty low toxicity. Id use gloves with methyl alcohol. Obviously, isopropyl alcohol as rubbing alcohol works as a cleaner. Ethyl alcohol-based rubbing alcohols probably work too - I think that they use them in Oz (called "metho" down under). To your point, methyl alcohol probably has some of the physical chemistry properties you want (that is, it might clean stuff and leave them oil and hydraulic-fluid-free), but I suspect that isopropanol might work the best of the three.
Summary: Methyl hydrate is methanol, and it might work to clean discs but I suspect that isopropanol or ethanol (look for rubbing alcohol, denatured alcohol, or methylated spirits) will work better.
*Conceptually - this is not how alcohol is made commercially.