Proper Prep

These are the couple of things I like to prep metal with prior to body filler.  For context, this is assuming that the project is already in bare metal.

  • First, the metal must be cleaned with either lacquer thinner, or a non acidic metal cleaner.
  • The 3M clean and strip discs work very good as the first step.  They clean very well, and don't miss much.  When this step is complete, the metal should be completely clean.  The part number is 7466  (there may be some spot sand blasting required.
  • 3M cubitron2 80 grit roloc discs work very good to 'grind' the metal before filler.  The abrasive is very sharp on these, so they create a whole lot of heat, and can/must be used at a low rpm.  The 80 grit leaves plenty of tooth for the body filler to stick to, but doesn't tear the metal up much at all.   Make sure the metal is ground thoroughly.   This is a very important step; everything else relies on the body filler adhering properly.   Part number 33392

Give these a try!  No, 3M is in no way endorsing this.  These are just some product I have found that work great.  Also, I love the Blue Point mini grinders.