Originally Posted by DirkaDirka
Ok if you are going to be applying bondo or Plastic filler you should apply it to bare metal that has been ground a little so that it will "stick" or "grab" onto the metal. Sometimes it is a waste of primer applying the bondo or plastic filler after you primer due to having to rough it up so it will stick. As for the new 1/4s you dont need to take them down to bare metal. Just need to rough them up so that the primer will stick to them. Just have to make sure that there is no surface rust starting when you go to primer them. Hope this helps
No offense Dirka but that is how it was done 20 years ago...I still do that because I don't mess with the epoxy primer since I do not have a booth . I use self etch and 2k Urethane....BUT the general consensus from Professionals now is epoxy first to seal everything then body work on top. EPOXY isn't the same as old school primer.