I'm wanting to redo my trailer in rubberized undercoating. It was recommended to me because there is no priming or major sanding it will just basically stick to anything. As far as I know all you need to do is make sure the trailer in clean and degreased. I cleaned up a spot last night to see how well it was going to look and when I went out this morning it did not stick at all. I could just scrape it off with my fingernail. Has anyone used this on their trailer? Any tips on getting it to stick? I'm guessing I'm just going to have to still sand it down and get it roughed up or something.... Any help is appreciated! Thanks