RE: Using Solartex
You do not even have to paint it if you do not want to. It is fuel proof as it comes. A clear coat or paint does make it easier to clean though as the weave does have a nasty habit of collecting dirt that is hard to clean out. But even then, Solartex (or any of the covering ending in ...tex such as Colortex, Worldtex etc.) is may favorite covering for large models.