I thought this might be worth mentioning. I've been restoring my MF12 http://gardentractor...f-12-rebirthed/ These GT have several welded seams in the sheet metal & if left alone I believe would be the first rust seen afterwards. After SB I took some Rust Reformer by Rustoleum & relly soaked these seams before priming. I have used this stuff in the past & it seems to be a good product along with some other brands out there. The metal turns many different colors before it finally turns black so don't panic. Thanks!