I still like POR 15. I never use it to bury rust, however. I sandblast, and then etch with there Metal Ready. And I only use it in places that "the sun don't shine," as they still haven't got the uv light thing fixed, and the paint fades. Inside door bottoms, inside fender bottoms, all with good, lasting results. But I also put Rust O Leum over the Metal ready, without problems. It is a great etch. Ospho is great too. There are so many ways, find one that works for you. Just my