Check whether fiber-cement siding needs abrasion at all, then restrict any approved hand scuff to the defect and control silica-containing dust.
Decide whether a painted wheel is safe to wet-sand, protect thin edges, and use a bounded test spot instead of a universal grit ladder.
Level minor defects and adjust sheen on fully cured marine varnish without cutting through edges or confusing sanding haze with final gloss.
Remove isolated nibs from finished oak paneling while preserving the surrounding sheen and avoiding broad burnished patches.
Refine a gessoed frame for gilding while preserving ornament, identifying unstable areas, and following the chosen leaf system.
Decide whether to preserve and scuff sound anodizing or remove it for a documented coating requirement, corrosion repair, or widespread damage.
Choose sanding sealer only as part of a compatible manufacturer system and test it against the first coat of finish on the actual wood.
Confirm full cure and determine whether color is encapsulated, exposed or migrating before wet-sanding an alcohol-ink epoxy surface.
Diagnose nibs, drag and true film defects before touching a shellac surface, then confine any leveling to a verified, fully ready test area.