What is in Krylon interior/exterior enamel colors and clears that they list them all as interior or exterior (I know its enamel) and that they dry in 10 minutes.

I have always looked for a reasonably priced exterior clear that dries super fast. I think of Krylon as kind of the WD40 of rattle can paint but it dries about 10x faster than rustoleum. Im wondering what the deal is with regards to a solvent based clear that will handle any substrate and be exterior rated.

I hope one of the Mods doesnt get randy and move this to the finishing forum because I am hoping for input from those building exterior painted sign work.