First NEVER apply epoxy primer over anything but metal. Many epoxy systems for example ppg's SV system doesnt like to harden over filler or some primers. The top layer will harden making you think you did a great job while a thin under linning will not harden. This layer allows the paint to peel off easily or will develop bubbles in the paint as the solvent begins to dry in the hot sun over time. So skip number 5. If you sand through to metal in some spots its ok, just use a urethane primer.
Epoxy primer doesnt like laquer thinner, so never use it as a reducer, use an enamel reducer. This is why I also never use laquer thinner to clean metal parts that will get epoxy primer, I always use acetone which makes the epoxy to metal really bond well.
Second use graded mixing cups to mix the epoxy and hardner, this is not a situation where you just pour it as close as you can. Epoxy is not like other paints, it needs to be exact down to the ounce and done in clean mixing cups.
Originally Posted by jomichael
Just so you know, I'm not a professional painter. I've been confused by this question as well and through trial and error and a lot of questions, I have boiled it down to this.
1. Media blast.
2. Clean with PRE or Lacquer Thinner.
3. Shoot Epoxy Primer.
4. Filler if necessary.
5. Add another coat of Epoxy Primer because you probably sanded off some of the epoxy to level that dent in step #4.
6. Lightly block sand with 320 or so.
7. Spray 2K Urethane primer over that for fine block sanding. Just use one system/brand if possible. I'm using Nason by Dupont simply because its available at the local auto paint store. Probably better out there, but it works.
I haven't gone beyond this point yet. Oh, if you blast some metal and don't get around to spraying it with epoxy and it flash rusts, I've used a little Phosphoric Acid to get rid of it. Spray on a rag and wipe fast, don't let it dry on the metal. Then wash again with PRE or Lacquer Thinner, then start at #3. Just keep water off the metal! I've tried these metal washes and though I might be doing it wrong, it flash rusts in front of my eyes! Maybe its the Florida humidity.
Now get ready for people to start disagreeing with me. Bring it on! I might learn some more! Ha!
55.2 chevy Napco