Like many of you with iron keeps, my '88 had developed a line of rust where the keep is attached to the hull. Every year meant srubbing it out, using a steel brush/sanding to remove it, then painting over it. Last year I read, on this site, that someone recommended going to an auto parts store and buying some Kleen Strip "Rust Converter". I cleaned up the flakes of rust, following the directions on the bottle, and applied a couple of thin, even coats. The stuff turns black like primer. I then re-painted as usual. Much to my surprise, and joy I might add, when I put the boat "on the hard" and let the bottom dry...NO RUST!!!!!!!! I don't know (nor care) how it works, it just does.