What spray paint really stops rust? I've tried a few brands, even kinds that claim to stop rust and still I get it. I sanded down some spots on the body of my truck to the metal a few years ago and primered them over. Never had an issue until before Christmas. I noticed rust showing through! I can sand it off and treat it. It's nothing big yet. But I don't want to have it cause any real issues. So what brands actually really stop rust? I don't want to try something else only to find out again it didn't work and this time I have some real rust issues. Thanks!