Wet sanding

Quick answer: Wet sanding is using very fine wet-and-dry sandpaper with water to level paint defects before polishing, so scratches, etching and orange peel can be removed more evenly and quickly than by polishing alone.

Wet sanding is using wet-and-dry fine-grit sandpaper to flatten the paintwork by hand. When polishing a car, we are removing a very thin layer of scratched paint, however the sponge pads we use are not flat, and they are soft, and so if we know we need to cut-back the surface to remove a scratch, we can use a very fine sandpaper on a flat sanding block or bobbin. This if both faster than polishing and will remove paint more evenly.

This technique is often used to remove light scratches and bird mess etching.

Wet sanding will also remove high points and reduce orange peel. After sanding, we continue polishing the car with compounds, polishes and sponge buffing pads on a random orbital polisher.

Wet and dry sandpaper is special waterproof sandpaper which is designed, so it can be used wet. Using water acts as a lubricant, and we can also wash away dust from the paper and panel.

In the US, this technique is sometimes called 'color sanding', which is a relic from the days when cars were painted with a solid base colour.

What it means

Wet sanding is a refined sanding technique used on car paintwork. Very fine wet-and-dry sandpaper is wrapped around a flat sanding block or bobbin and used with water as a lubricant. Instead of relying on soft polishing pads, you use the flat abrasive to knock down high spots in the clearcoat, level light scratches, bird-lime etching and texture, and then follow up with machine polishing and compounds to remove the sanding marks and restore full gloss.

Why it matters

Levels the surface more evenly: A flat sanding block cuts the tops off high spots in the paint, giving a smoother, more uniform surface than relying on soft polishing pads alone.
Tackles defects polishing can struggle with: Localised issues like bird mess etching, light key marks and nibs in the clearcoat can often be removed more cleanly by careful wet sanding than by heavy compounding.
Prepares for a higher quality finish: By reducing texture and orange peel before polishing, wet sanding allows the final machine polishing stages to achieve a sharper, more mirror-like finish.

Where you’ll see it

You’ll see wet sanding mentioned in bodyshops, smart repair centres and higher-end detailing studios, especially in relation to flat and polish work, orange peel removal, bird-etch removal and key scratch repair. It is commonly used on bonnets, roofs and repainted panels where a particularly flat, show-car style finish is required.

Context

Wet sanding sits between dry sanding and pure machine polishing. It is usually carried out with fine grades such as P1500–P3000 wet-and-dry paper, often after any heavier dry sanding has been completed. Once the panel has been flattened with water and paper, it is then compounded and polished by machine to remove sanding marks. In the US, similar work is often called colour sanding, a term that dates back to the days of single-stage paints.

Common mistakes

Using too coarse a grit or too much pressure, leaving deep sanding scratches that are difficult or unsafe to polish out.
Wet sanding edges, creases and thin areas without checking paint thickness, risking strike-through to primer or bare metal.
Not keeping the surface properly lubricated and clean, allowing abrasive slurry to clog and scuff the paint instead of cutting cleanly.
Skipping thorough machine compounding and refinement afterwards, so dull, sanded patches or fine sanding marks remain visible in the finish.

Written by Danny Argent. Last updated 17/11/2025 17:35