alwaysFlOoReD said:So I sprayed down my truck with a product from por15. It is called pre-primer. It has phosphoric acid, zinc phosphate,water and one other fairly innocuous chemical in it. I did like the directions said and sprayed and kept wet for 10 to 20 minutes. I looked at it yesterday after letting it dry for a couple of days and it looks like galvanizing that you see on fence pipe. There is a residue left that I'm supposed to hose off, I'll do that later this week. I've used something similar before on rusted metal and after wire wheeling the rust off, it turns black after being applied and drying. I'm guessing that if there is no rust [like my sand-blasted truck] that there is no reaction between the rust and product to turn black. Anywho, I'll update a little later this week.