Scratches Are Too Deep
The surface has visible sanding marks, gouges, or scratches that remain after sanding.
Deep scratches remain after 80 grit
80 grit removed material but left deep sanding scratches. Recommended grit: Step through 120, 180, then 220 or 320.
320 grit does not remove 180 grit scratches
Scratches from 180 grit remain after sanding with 320 grit. Recommended grit: Use 220 or 240 before returning to 320.
Coarse scratches show on wood
Wood still shows visible scratch lines after prep sanding. Recommended grit: Use 120 to remove heavy marks, then 180 and 220 for prep.
Scratches remain on metal after prep
Metal shows straight or uneven sanding scratches after prep. Recommended grit: Use 180, 220, 320, then 400 or 600 for finer prep.
Deep lines remain on clear coat
Fine sanding leaves some deeper lines in clear coat. Recommended grit: Wet sand through 1000, 1500, 2000, and 3000. Use 800 only to correct deeper lines.
Dry sanding leaves dust scratches
Dry sanding leaves visible dust scratches on the surface. Recommended grit: Use the grit needed for the task, then refine one step finer after cleaning. For prep work, move from 220 to 320 or from 320 to 400.