I never used epoxy primer just prepped using sander. To form a good key cleaned with white spirits and applied a mist coat and two full coats. I wanted a heavy finish , I went for a landrover colour aintree green the colour of my 110 defender. But the raptor diluted it to a lighter shade I didn’t like it at first but it grew on me , wheel arches I done black. . Now here’s the thing ! My friend reversed his truck into my wheel arch. The arch dented the raptor never cracked or split I pushed the dent back out the raptor just popped with it as I said it’s a durability is. Amazing. Am in construction. So it gets abuse