Epoxy primer over urethane primer?

[low91]

I'm in the process of prime'in a door and fender the fender is down to bare metal and the door is primed with z-chrome urethane, I don't want to use the z-chrome on the fender, so I was thinking about trying epoxy primer but i also have to recover part of the door. would it be ok to spray the epoxy over the urethane? Is epoxy good to use if your not planning on painting for a few months?

[bnmotorsports]

epoxy primer is a "non-sandable" primer its meant to be used as a wet-on-wet primer, but yes its ok to spray over urethane primer. for the bare metal you want to use a self-etching primer, then urethane over that then block and paint