PPG Expoxy primers will stick to it just fine. Go over the car with 180-80 grit sandpaper on a DA (should do that anyways) pre clean with solvent based W&G remover and then water based W&G remover and that should be all that's needed. That is how I have done it anytime we had a car soda blasted. Came out nice and you could see where previous owners ground the metal and added filler for dents, seen original leading around the roof and quarter seem on a 66 malibu, etc.