---
title: "Which sandpaper grit for plastic?"
description: "Start at 320-600 wet for scratches, work up to 2000, then finish with a plastic polish — and keep it cool. The ranked options, the technique that changes the outcome"
url: https://atoneplace.net/which/sandpaper-plastic/
site: "At One Place"
---

# Which sandpaper grit for plastic?

**Which sandpaper grit for plastic?: Start at 320-600 wet for scratches, work up to 2000, then finish with a plastic polish — and keep it cool.**

Plastics have low softening points and poor thermal conductivity, so friction heat stays right at the surface: sand dry or fast and the plastic smears and melts rather than abrading, leaving a hazed area that no amount of polishing recovers. Wet sanding fixes that by carrying the heat and swarf away, and silicon carbide paper is used because it is waterproof and cuts cleanly. On stressed parts there is a second risk — some polishes and solvents can start crazing in acrylic and polycarbonate — so use a product intended for plastics and test on a hidden area. Headlight restoration is exactly this sequence, and it fails without a new UV clearcoat afterwards, because the original factory coating is what was sanded off.

## The options, ranked

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

| Option | Good at | Bad at |
| --- | --- | --- |
| 320-600 wet silicon carbide | Removes light scratches and haze from acrylic and polycarbonate without deep new marks. | Deep gouges need a coarser start, and every coarse grit lengthens the polishing that follows. |
| 800-2000 wet | Refines the surface to the point where polish can bring back clarity. | Slow, and skipping a grade leaves scratches the polish cannot remove. |
| Plastic polish or cutting compound | Finishes the job and restores optical clarity on headlights, screens and acrylic sheet. | Heats the surface if machine-applied hard, which can craze it. |
| Flame or vapour polishing | Restores a truly glass-like edge on acrylic. | Specialist and easy to ruin the part, and solvent vapour polishing is genuinely hazardous. |

## Technique that changes the outcome

1. Wet sand with silicon carbide paper and plenty of water
2. Move up through the grits without skipping, wiping clean between each
3. Keep the surface moving and cool; stop if it feels warm
4. Finish with a dedicated plastic polish, then protect it — a clearcoat on headlights, an antistatic cleaner on acrylic

## What goes wrong

- Dry sanding, which melts and hazes the surface
- Household solvent cleaners on acrylic and polycarbonate
- Restoring headlights without recoating them; they yellow again within months

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

## Common questions

### Which sandpaper grit for plastic?

Start at 320-600 wet for scratches, work up to 2000, then finish with a plastic polish — and keep it cool.

### What should I avoid?

Dry sanding, which melts and hazes the surface Household solvent cleaners on acrylic and polycarbonate Restoring headlights without recoating them; they yellow again within months

## Related pages

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## Sources

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