Mitch/stock49, first of all let me thanks the both of you for the well explanations. Sound like you both been in this business a long longer than me. Maybe I don't need por15 after all. All I really want and I'm after is for the bottom of my frame, floors, suspension,etc to look cleaner and all black. I cleaned any surface rust there was. Now I just want everything to be black actually semi gloss. Does the only reason why I went with por15 in the first place, and because it can be applied by brush. I know I can shoot the whole thing with a gun but the car is already painted and I be afraid to get over sprayed. Is there anything out there maybe cheaper that I can applied by brush that will still work?