The Stovebolt Site Forums The Shop Area Paint and Body Shop U-Pol 2K vs. Epoxy Primer

OK, I've stripped the cab on Ugly '54 down to bare metal, coated it with Jasco phosphoric acid wash to delay rust and now I'm ready to prime. Would it be OK to use U-Pol 2K urethane primer directly on the treated metal or should I invest in epoxy primer for the first coat then use the U-Pol as a primer/filler?

http://www.u-pol.com/datasheets/tds/S2020-TDS-US.pdf

http://www.u-pol.com/product-cat/35/acid%238%E2%84%A2-acid-etch-primer.htm

Urethane primer irregardless of brand is NOT meant for and should never be applied to bare metal.

Epoxy primer should be applied to bare metal. You need to check the tech sheets on your epoxy or email the company and see if their epoxy is compatiable with that metal treatment you applied. Most epoxies can not be applied over metal treatment or metal etch type products.

Read the tech sheets of each product you plan to use prior to usage...Eric

The best way for you to go for what you have done, is put on a coat of Self etching primer, then youre good to go with the urethane primer.
Self Etching primer has an acid additive that bites into the metal, & will work well with the phosphoric acid. This is another alternative to using Epoxy.