I bought the Por 15 six pack (small cans), and I'm in the process of wirebrushing/grinding/sanding all the rust I can off my frame. As I get the layer of surface rust off, there is a pretty tough black layer on there before I get to shiny steel. I don't think the guy who owned it before me did anything to the frame. Is this part of the oxidation of the metal? Or is it more likely to be a coat of a Por15 type coating?
Also, I didn't pay for the Metal Ready prep stuff, am I still going to get good results just applying the Por 15 to the metal surface?
