An epoxy primer is generally an epoxy with solvent added.
urethanes generally go over an epoxy as epoxies bond really well and urethanes
don't.

Don't see how there would be any difference with whatever kind of epoxy you have
under the urethane, just watch out for amine blush which would ruin the bond.


paul oman
progressive epoxy polymers
www.epoxyproducts.com