I have had a terrible problem with a rusty gas tank. I have done the clean with vinegar method and it gets the rust out great. The problem is that my tank flashes rust again really fast. I read somewhere online that coating the tank with automatic transmission fluid will stop flash rust. Has anyone ever done this? and if I try what will happen when I put gas in the tank and try to run it? I dont want to make things worse. Also if you know a way to stop flash rust I'll take any suggestions I can get.