Originally Posted by Pats55
The misinformation is that their led to believe that they paint this black urethane over the rust and its sealed forever.That is nonporous.Not exactly true. For many years they were never told how many coats to apply.The name of this coating system is The three coat polyurethane system. It was named that for reason It works better over rust, because the only thing it'll stick to is rust.it's difficult to paint over so it's not really a primer. It doesn't take sunlight so not really a top coat. It's great for a application under a car when used with the correct primer. Brushes out beautifully got an extremely high-gloss and is pretty chip resistant.
You won't have a difficult time convincing people here that POR, and it's various analogues, sucks. You're just preaching to the choir now, brother.