So I cant use a product with acid on any layer touching the epoxy primer? And they do make 2k epoxy primers you just pull a plug on the bottom of the can and shake and you have a few hours to use it...
Etching primer has phosphoric acid in it and these products are only for direct to bare metal. The acid etches a fine profile in the metal and sticks without having to scuff the surface to promote adhesion. You can't put this stuff over rust converter type products.
Rust converters contain tannic acid which is nothing like the acid in self etch primers