triton is right. think about the rust repiar, not the paint. forget the black dull finish. fix the rust and fix it right. body putty and sand it down smooth. then get some rustoleum red oxide primer and brush or spray over the area. do all the rusty spots and repiar one at a time. dont worry about "how it looks" when in progress. when you get done, spray paint the bottom foot of the truck a contrasting color, or get a close match for your original paint untill you paint the entire truck. the repair procedure is much more imortant than the paint.