Home Depot lists several 'rust converter' products. A quick google search and I found this product.
http://www.eastwood.com/eastwood-rust-converter.htmlI have not used either products. I did use something about 10 years ago, it was supplied by a paint company to my work to try out. As I recall it would have a name like 'rust n a me' and it basically converted the surface rust into a very tough primer that was easy to paint, and a hard surface that accepted paint easy. We used Williams Paint as our supplier, and they probably had a rust seminar one day at lunch and presented a 'new' product for everyone to test out. Over the past 10 years, the company that produced that product could have been bought out, and names change, ect.
Good luck,
Fred.
