Etch or wash primers – Go direct to bare metal and assist in adhesion but are mostly there to serve as a conversion coating to prevent a rock chip from getting out of control. Do not put over filler. Do not put under filler.
Epoxies – Can go direct to metal and work well by themselves. There is debate as to weather it is best to put over an etch or not, that’s personal preference and experience. I have done both ways with success. Can go over body filler and can go under body filler...
paint basics
