I first used Eastwood rust converter and followed the directions,then poured there black rust incapsulating paint in and with the help of a few friends moved the panels around to allow the paint to cover all sides, After that dried I then poured in black Rustoleom and repeated the process I did this for the inside of my doors as well. lay down some plastic for the spillage. It was not pretty but it will not rust. Por 15 would work as well but I found this to be less expensive. Good luck.