I used the POR15 tank sealer on my tank. It came out really well, but I am not anywhere near the point in my build to put fuel in it. All I can say from my experience is this - follow all prep instructions to the letter. Your best results with any product is to not cut any corners or eliminate recommended steps. I used the POR15 Cleaner/Degreaser before sealing per the tank sealer instructions. I also used a phosphoric acid solution to eliminate the rust, and switched from a water rinse to a denatured alcohol rinse. Any water rinse will flash rust. Your pre-sealer surface prep is the key to success with tank sealers.