Pitted? Well, it cannot penetrate very deeply. Mostly good for surface rust or as a metal etch/primer. I coated a bare piece of metal 10 years ago and it is still shiny. The other piece I didn't coat is covered in rust. It is really amazing how well it can protect. I paint over it all the time and have never had a problem. I wiped the entire inside of my car down with it after I gutted it. Now if the metal is rusted on the backside and the Ospho can't reach it, it WILL rust through. But if you can get to both side you are golden.
