Not a vehicle but I thought you all would be the best to ask a rust treatment. We bought this water trough to use as a soaking tub when it gets hot in the summer. We had a pool that got old and realized we really didn't need another, just somewhere to cool off. It is/was galvanized but the coating wore through. We bedlinered it then when that didn't work my Wife did a nice paint job. That too didn't last. Any suggestions on what we could use to stop the rust. Thanks. Jim