Rust under factory paint

Doupont makes a metal conditioner I believe the part # is 5717s and 18? It is a two step system. It is a acid etch and it remove all the rust. The second part is a nuetralizer. I have use this on many sun baked and blistered roof that started to rust ( did my fairlane and had no issues). Then apply a good quality self etching primer. But that is just my 2 cents.

Thanks
James From
PST Marketing
1-800-247-2288
Ext 316