After seeing this subject asked and talked about for 20 years, I think it should be pinned to the top of the list that 1) there is no such thing as a free lunch, 2) there is no such thing as a true, cheap, fuel proof finish out of a rattle can. I still is a bad idea to mix a lot of different materials on the surface of an airplane, especially the wings, and especially if you are still in the beginner/intermediate/frequent crasher stage and have to repair the airplane at any time. The two part (don't know where the 2K thing started) car finishes are the most suitable these days, are available in a lot of forms and in small quantities. The Nason system fro DuPont (or whatever they call it now) come ready to spray, just add hardener and can be had in quarts. Lots of guys have posted good results on here with it. If you don't have or want a compressor and spray equipment, there are some small, refillable can type applicators that would work for this as well. The best overall, lightest finish is still dope, but is not as fuel proof as it once was, so to compensate, some have resorted to applying the two part clears on just the nose of the airplane and maybe the wing roots, where any raw fuel may get splashed or drip. This makes repairs easier because you know what you put down and where and can sand through it so you can reapply more dope. No real easy but doable. The only way to avoid all of this is to fly electric and you can paint and finish with damn near anything. Lots has been posted on line here and other forums on the different finishes that are being used also, including different types of the new epoxies.
Type at you later,
Dan McEntee