Step 7: Sand and Touch Up Paint
Once the exterior filler material is completely dry, you need to sand it flush with the rest of the bumper. Affix the 200 grit sandpaper to the sanding block and sand the whole area of the crack until the filler compound is flush with the rest of the bumper. Completely remove all dust and grit from the bumper surface and carefully use the touch up paint to paint over the area of your repair of the plastic bumper.