There is nothing really in a single component spray can. There is some stuff out that is ion a spray can, that you activate a catalyst in the can and you have a varying amount of short time shelf life before it all kicks off. If you have spray equipment, look into the Nason two part system that is what used to be DuPont. It comes in quarts, is thinned ready to shoot, just mix up what you need with catalyst. Do a search on the forums for it. We have several guys that are world class luthiers ( they make stringed instruments) and several of them use it. Only concern yourself with the nose and tank area and the leading edge of the wing near the fuselage. No need to do the whole airplane for fuel proofing. Make your trim paintings, then shoot clear dope. If all OK then do the nose and such with the Nason. If you ever have to do a repair on the wings and such, it will be lots easier just dealing with dope. It will also be a bit lighter as the dope will gas off, but I don't think the two parts stuff does.
This is a subject that has been asked about almost as much as "How to you set up a FP, LA. 40?" There is lots of stuff from the hardware store that in opaque colors is fairly fuel resistant, not fuel proof, but there has been a world wide search for the magic bullet clear that is fuel proof, and I believe it doesn't exist in a single part spray can. Top Flite had their Luster-Kote paint out, and their clear wasn't too bad, but there were problems just spraying that stuff and with Great Plains going bankrupt, I think it was pulled from the market.
Type at you later,
Dan McEntee