---
title: "Which sandpaper should I use for wet sanding?"
description: "Silicon carbide wet-or-dry paper, water with a drop of detergent, a rigid block, and 800 grit upwards. The ranked options, the technique that changes the outcome, an"
url: https://atoneplace.net/which/sandpaper-wet-sanding/
site: "At One Place"
---

# Which sandpaper should I use for wet sanding?

**Which sandpaper should I use for wet sanding?: Silicon carbide wet-or-dry paper, water with a drop of detergent, a rigid block, and 800 grit upwards.**

Wet sanding is not about the water lubricating the cut; it is about removing swarf and heat. Loose particles that stay on the surface are exactly what put deeper scratches into it, and heat is what softens paint and plastic into a smear. So the technique is: plenty of water, frequent rinsing of both the paper and the surface, and consistently light pressure. Use a rigid block wherever the goal is flatness, since fingers follow every ripple, and a soft interface pad only where the shape is curved. Check progress constantly by squeegeeing the surface dry — a wet surface hides exactly the defects you are trying to remove.

## The options, ranked

*Ranked best-first for the stated job. The third column is why the others exist.*

| Option | Good at | Bad at |
| --- | --- | --- |
| Silicon carbide wet-or-dry paper | Waterproof backing and a sharp friable grain that keeps cutting; the standard for paint, clearcoat and plastic. | Breaks down faster than aluminium oxide when used dry. |
| Aluminium oxide paper | Tougher and longer-lasting for dry work on wood and metal. | Its backing is usually not waterproof, and it clogs on wet paint. |
| Foam-backed abrasive pad | Follows curves without cutting through on the high points. | Cannot flatten a surface, because it follows what is already there. |
| Water with a drop of detergent | Cuts surface tension so the water spreads and floats swarf out of the abrasive. | Must be rinsed off completely, or the residue interferes with polish. |

## Technique that changes the outcome

1. Soak the paper for a few minutes before starting
2. Add a drop of detergent to the water so it spreads instead of beading
3. Rinse the paper every few strokes and keep the surface flooded
4. Use a block for flat panels and change direction between grits so you can see the previous scratches disappear
5. Squeegee dry to inspect before moving up a grit

## What goes wrong

- Letting the surface run dry mid-stroke
- Working on a thin coat or on an edge, where you will cut through in seconds
- Skipping grits — the coarse scratches simply survive to the polishing stage

> Compiled practical guidance rather than a published standard. Product formulations vary by brand and market, so read the label — and where the work is structural, electrical or gas, the regulations that apply where you are govern rather than anything here.

## Other sandpaper grit questions

| For | Use |
| --- | --- |
| Bare wood | 80 to 120 to 150 on softwood, finishing at 180 or 220 on hardwood — and stop there, because over-sanding ruins stain. |
| Stripping paint | 40 to 80 grit open-coat aluminium oxide or ceramic — but test for lead paint before sanding anything painted before the 1990s. |
| Rusty metal | 60 to 80 grit to strip scale, 120 to 180 to blend — then prime the same day, because bare steel flash rusts within hours. |
| Between coats | 220 to 320 grit with almost no pressure — you are knocking off dust nibs, not removing the coat. |
| Plasterboard filler | 120 to 150 grit to level joint compound and 220 for the final pass, ideally on a mesh with a vacuum attached. |
| Plastic | Start at 320-600 wet for scratches, work up to 2000, then finish with a plastic polish — and keep it cool. |
| Car body filler | 80 grit to shape, 180 to refine, 320 before primer and 400-600 on the primer before paint. |
| Final finish | 400 to 600 dry, or 800 to 2000 wet on a fully cured film, followed by a polishing compound. |

## Common questions

### Which sandpaper should I use for wet sanding?

Silicon carbide wet-or-dry paper, water with a drop of detergent, a rigid block, and 800 grit upwards.

### What should I avoid?

Letting the surface run dry mid-stroke Working on a thin coat or on an edge, where you will cut through in seconds Skipping grits — the coarse scratches simply survive to the polishing stage

## Related pages

- [Which sandpaper grit for bare wood before finishing?](https://atoneplace.net/which/sandpaper-bare-wood/)
- [Which sandpaper grit removes paint?](https://atoneplace.net/which/sandpaper-stripping-paint/)
- [Which sandpaper grit removes rust?](https://atoneplace.net/which/sandpaper-metal-rust/)
- [Which sandpaper grit between coats of paint or varnish?](https://atoneplace.net/which/sandpaper-between-coats/)
- [Which sandpaper grit for plasterboard and filler?](https://atoneplace.net/which/sandpaper-drywall/)
- [Which sandpaper grit for plastic?](https://atoneplace.net/which/sandpaper-plastic/)
- [Which sandpaper grit for car body filler?](https://atoneplace.net/which/sandpaper-body-filler/)
- [Which sandpaper grit for a final finish?](https://atoneplace.net/which/sandpaper-final-finish/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)