Originally Posted by
Outrider6
I am dealing with this issue too now, as I am building a SIG Cub. Sky blue fuelproof paint seems to be impossible to find, but at least I found a fairly fuel-resistant white paint in Rustoleum Appliance Epoxy spray. "Epoxy" is a marketing lie, as it isn't really epoxy at all (probably just a tough enamel), but it held up ok in my sample test. Rubbing some fuel on it didn't seem to dissolve it, but when I let some fresh fuel soak on it, the paint peeled off some. What I did was spray inside a plastic margarine type container. I know I didn't get a really good paint bond to the material, so that is part of the peeling problem. But the good news is that the fuel didn't seem to actually dissolve the paint.
The "epoxy" in this case is a somewhat modified version of what is known to be real epoxy paint. Just like epoxy glue, if you were to mix both components and put them in a spray can, they would harden or at least turn into a useless glob, BUT to get around this problem, what the manufacturers did was to add a chemical to the paint that would evaporate during the drying process, but while it is contained in the paint it would serve as a barrier between part A and B to prevent there being a chemical reaction and cause hardening in the can.
Normal epoxy paint (where you have to combine ingredients before using) is not reliant on the evaporation of an inhibitor chemical and as such will harden in a predetermined amount of time without the need to breathe or dry. Since drying is essential to this type of one step epoxy, the hardening process can be somewhat prolonged, but eventually it gets there.