I was going to go at it this winter on the underneath. I was planning to wire brush off as much as possible and use some of that rust reverser stuff prior to paint. Anybody have any helpful hints? Does the film left from the rust reverser stuff stick well or is it better to paint on bare metal? With heavy rust, the surface is usually too rough to be able to get all the rust with brushing/sanding so I was thinking the rust reverser stuff was the way to go. Any chance the stuff will cause long term damage like slowly eat away the metal? It must have some pretty rough chemicals in it to react with the rust.