After I media blasted my cab and front end parts I hit it with phos acid cleaned with wax and grease remover and primed with epoxy then with in the window went over that with urithane primer surfacer. I then block to find the low spots with 80 grit. I ended up sanding most of the urathane off and skim coated with filler over the doors and fenders. I have heard that filler over urathane is ok from some and not from others. What do you guy's say and why. I will probable just epoxy the bed and fill over that after scuffing it up, but I wondering what the truth is about this. Thanks.
