Sandpaper Grit Guide: Which Indasa Grit for Each Job
Choosing the right grit is the difference between a fast cut and a ruined surface. This guide explains how abrasive grit numbers work and recommends grit ranges for common automotive refinishing, woodworking, and metal-finishing tasks using Indasa abrasives.
How grit numbers work
The grit number describes how coarse or fine an abrasive is: lower numbers are coarser (faster cut, deeper scratch) and higher numbers are finer (slower cut, smoother finish). Most Indasa abrasives use the European FEPA "P" scale (e.g. P80, P400). Always sand in steps rather than jumping many grits at once.
Grit ranges by job
| Task | Typical grit range |
|---|---|
| Heavy stock removal / paint stripping | 40–80 |
| Shaping body filler | 80–150 |
| Leveling primer / feather-edging | 180–320 |
| Final sanding before paint | 400–600 |
| Wet sanding / denibbing clear coat | 800–1500 |
| Pre-polish / fine refinishing | 2000–3000 |
| Bare wood sanding | 80–120, finishing 180–220 |
Sand in steps (grit progression)
Each grit should remove the scratches left by the previous one. A common progression is to step up by roughly 50–100 grit at a time (for example 120 → 180 → 240 → 320). Skipping too far leaves deep scratches that finer paper cannot erase efficiently.
Wet vs. dry sanding
Dry sanding with dust extraction is fastest for shaping and leveling. Wet sanding (with water as a lubricant) is used at high grits to refine clear coat and remove imperfections with minimal heat and clogging. Use abrasives rated for wet use, such as Indasa Rhynowet, when wet sanding.
Frequently asked questions
What grit should I use to sand body filler?
Shape body filler with 80–150 grit, then refine with 180–240 before priming.
What grit do I use before painting?
For most automotive topcoats, finish bare and primed surfaces at 400–600 grit before painting; follow your paint manufacturer's recommendation.
What is the difference between P-grade and standard grit?
P-grade is the European FEPA scale used by Indasa. At very fine grits the P scale and the North American CAMI scale diverge, so a P800 is not identical to an 800 CAMI; match within one scale.
How many grit steps should I skip?
Generally step up by about 50–100 grit at a time so each grit removes the previous scratch pattern; skipping further leaves scratches that are slow to sand out.
What grit is best for wet sanding clear coat?
Wet sand clear coat in the 1000–2000 range, then move to polishing compounds for a final gloss.