Step-By-Step – 9 Step To Apply and Sand Body Filler

  1. •If the repair has been welded, mix and apply fiberglass filler to repair area.
  2. •Sand the filler with 36 grit.  There is no need to use a finer grit as body fill will be applied over the fiberglass.  All you need to level the glass filler.
  3. •Mix and apply body filler over the repair area.  Cover and extend body filler over fiberglass.  Do not extend the filler onto the paint surface.
  4. •Block sand (cross sand) the filler with 36 grit sandpaper.  (This step can be done before the filler is completely dry to reduce the amount of sanding required.)
  5. •Repeat step if there are still lows.
  6. •Allow to fully cure (15 to 20 minutes) and spray with guide coat.
  7. •Block sand (cross sand) with 80 grit sandpaper.  Sand just enough to remove guide coat.  If guide coat does not sand off in an area indicates a low and additional filler will be needed.
  8. •Optional: Either apply guide coat and block sand with 150 grit; Or, Apply a coat of finish glaze over entire repair area.  Remember, glaze can be applied over sanded paint too.
  9. •Finish filler or glaze by blocking with150 grit.