For most automotive sanding tasks, you'll use wet/dry sandpaper with a grit range between 800 and 3000. The exact grit depends entirely on the job: removing clear coat scratches, smoothing primer before painting, or tackling surface rust. Using the wrong type or grit can permanently damage your car's finish.
The most critical rule is to always start with the finest grit that can effectively handle the task and gradually move to finer grits. For instance, if you're sanding a clear coat to remove light scratches, you might start with 1500-grit paper and finish with 2000 or 3000-grit to create a smooth, haze-free surface ready for polishing. For sanding primer before applying base coat, 400 to 600-grit is typically used to create a "tooth" for the new paint to adhere to.
| Sanding Task | Recommended Grit Range | Key Considerations |
|---|
| Removing Orange Peel | 1000 - 2000 | Use with a sanding block and plenty of water (wet-sanding). |
| Smoothing Primer | 400 - 600 | Creates a slight texture for paint adhesion; avoid cutting through to metal. |
| Feathering Edges | 800 - 1500 | Blends repaired areas into surrounding paint; requires a delicate touch. |
| Final Polish Prep | 2000 - 3000 | Used after coarser grits to eliminate sanding marks before compounding. |
| Surface Rust Removal | 80 - 220 | Start coarse, but be aggressive only on bare metal, not surrounding paint. |
Always use the sandpaper with a backing pad or block to maintain even pressure. For paintwork, wet-sanding is strongly recommended. It lubricates the surface, reduces clogging of the sandpaper (a problem known as "loading"), and minimizes heat buildup that can warp thin panels. Use a dedicated sanding lubricant or a few drops of dish soap in a bucket of water. Change the water frequently to avoid grinding removed particles back into the surface.
