Por 15 is rock hard stuff! I like it for bumper brackets. Fills up imperfections and wont scrape off. Not very good on nonrusted metal though. The biggest problem I had with it is the solvent popping while curing . Its so humid here in Jacksonville and the por15 likes to harden up too fast. While applying it looks great, but as it dries up u get lots of bubbles in the finish.
