after stripping the old covering off my airplane alot of places are fuel & oil soaked. what can i do to get it ready to cover? thanks alot conk

Get some Balsarite. They come in two mixtures one for fabric and one for film covering so be sure you buy the right one. Works great. Pete

I use balsarite too, I give it a light sanding when it dries. Like Rocketman612 said, make sure you get the right mixture for the type of covering your going to use.