I have searched and didn't really find much, but was wondering if any of you use rust converters to finish your pieces. From what I have read they seem to be a good durable finish which can be used as is, or some are ready to paint over, no priming needed.

I have used them and they do work. It is some type of phosphoric acid if my memory is correct. They take paint very well. One of the best ones I have used came from England. Look for antique auto restoration.