If these are slightly rusted or pitted panel i would use naval jelly and steel wool. Rinse off good and hit with 80 grit sandpaper. You don't want to put epoxy over anything but clean dry metal sanded with 80 to 120. 80 preferable. If you have a couple pics email me @ aero46chevy@msn.com . I can give you a better Idea if I could see what you are dealing with.
John
