Use the lightest compatible pencil mark on bare material or a coating that can safely accept it. Never mark a delicate, porous, or finished surface without a scrap test.
Remove support nubs by cutting or scraping when appropriate, then use abrasive for the remaining proud witness—not as a substitute for controlled support removal.
Use a conversion chart to choose a starting comparison, never as proof that two abrasives will leave identical scratches. Mineral shape, coating density, backing,...
Map the mismatch before cutting: separate height, bevel geometry, color, pore appearance, and sheen. Decide whether the repair is a board-only treatment or a larger...
Use 60 only for heavy, confirmed removal on material with adequate allowance; use 80 when the defects are shallower or control matters more than speed.
Choose 500 when a stable surface still needs measurable refinement; choose 600 when correction is complete and you are reducing the scratch before coating, polishing,...
Use 180 to remove the verified remnants of the previous grade or flatten small high spots; use 220 for the final light refinement only when the coating or finish...
Begin at 1500 only if texture or coarser scratches remain within a safely sandable coating; begin at 2000 when the surface is flat and the objective is a smaller,...
Choose 150 for leveling shallow tool marks or firm filler; choose 180 when the shape is established and the job is to refine without changing it quickly.