January 25, 2006
Sanding Automotive Body Filler
First, the bodyman finishes the filler work to 80 grit, then a quick trip over the filler and old paint edge with 180 grit on a DA sander (lightly to not destroy the shaping), then feather edge the surrounding repair with 320 grit on a DA sander. Scuff a little past the area to be primed with a 6 x 9 maroon scuff pad. Prime the area and after it has cured any areas that need slight block sanding can be done with a 320 grit on the primer.
Basic Guidelines for Automotive Sanding:
24-36 grit for paint removal, bare metal Bondo prep and roughing out the filler with an air file or hand board.
60-80 grit for smoothing out the rough scratches from the previous operation and shaping fine contours.
80-180 grit for further smoothing in preparation for high-build catalyzed primers (with hardner) or 240-320 grit for lacquer-based (non-catalyzed) primers.
220-600 grit for final sanding prep before paint, following the manufacturers guidelines on their product information sheet.
600-2000 grit for sanding clear coats or for removing minor surface imperfections prior to polishing and buffing.
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