I think there are really only two ways to get rid of rust. You can isolate it so it can not get any air, no air, no more rust, or you can cut it out and replace the metal. If it is just surface rust, I've had good luck with plain old Rustoleum paint. I get all the loose rust off and sand or grind it down to where everything is solid and tight and paint over it. It seems to work well. I like the brushable kind better than the spray on type, because it seems to me it has more solids in it, however I use the spray when I have a place that is hard to reach. I only use the Rustoleum on places that are not visible, or will not be painted with the regular auto paint, like the frame, under fenders, etc. I have a friend who is a painter,and he is very strict about sealing all seams and joints from the back with either brushable sealer, or the kind you use with a caulking gun. This is to keep out water and air. Most rust comes from the back side of the metal, where you don't see it until one day you are cleaning the truck, and poke a hole in a rocker or something else. Allen