Epoxy is listed as primer, add reducer it becomes a sealer. Someone explain if I am wrong. I think of sealer going on before the toppoat, and the epoxy primer as the base over bare metal, and before filler.
Generally epoxy is not sandable, but SPI epoxy is sandable for instance. .
There are also Urethane primers, and polyester primers that are for high builds and self leveling.
Be aware with the gravity gun, there is a lifter at the base of the cup, that sometimes needs to be remove if shooting a thick material.
This all is just my opinion.
