There are several types of enamel. Enamel paints are really just a group of paints that share a characteristics of crosslinking as it hardens and not being significantly softened by the solvent that originally bore them once try, and that they are hard and glossy like the vitreous fired enamel you find on appliances.

Early auto enamel paint was oil-modified polyester, later enamels are acrylic or latex based. Rustoleum "Enamel" shares very little chemistry with the real, old style polyester enamels. The gasoline is actually softening and breaking the crosslink. I can't figure out what is actually in today's Rustoleum (they changed the formula recently), but I suspect its probably latex based, which is softened by gasoline quite easily.

Lacquers don't crosslink like enamels, but they may also be gasoline resistant as long as the pigment doesn't loose adhesion from it.

Paint & Body Shop moderator
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