Paint Scraper Guide: 70mm vs 175mm & How to Prepare Surfaces Before Decorating

Good decorating often starts before the paint tin is opened. Loose or flaking material, residue and uneven areas can interfere with the next stage, so a scraper is a useful first tool when the surface needs firm mechanical preparation.

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The main choice in our decorating scraper range is between a narrower 70mm blade and a much wider 175mm blade. They do similar jobs, but the working width changes where each one is easiest to control.

70mm vs 175mm scraper: the quick answer

• 70mm scraper: better suited to targeted scraping, smaller areas and places where you want a narrower working edge.
• 175mm scraper: useful for broader areas where a wide blade can cover more surface with each pass.

Neither size should be used blindly. Check the underlying surface, use appropriate PPE and avoid applying more force than the material can safely take.

When should you use a 70mm scraper?

The Roll Roy Heavy-Duty 70mm Scraper uses an extra-hardened carbon steel blade with a wooden handle. Its narrower edge gives more targeted control than the 175mm version.

It is a practical choice for smaller patches of loose or flaking paint, stubborn residue on suitable surfaces, renovation work and areas where a broad scraper would be cumbersome.

When is a 175mm scraper more useful?

The Roll Roy Heavy Duty 175mm Scraper has a much wider blade. That makes it useful when you need to work across a broader area and want to cover more surface with each pass.

Typical uses include removing loose and flaking paint, preparing larger wall areas and general renovation or maintenance work. The wider blade does not mean more force should be used; the surface still needs to be checked before scraping.

Should you scrape or sand first?

If a surface has loose or flaking material, scraping is normally the logical first mechanical step because it removes material that is already failing. Sanding is then useful for refining the prepared area, smoothing transitions and creating the level of finish needed for the next stage.

The exact preparation sequence depends on the surface and the coating system you plan to use, so follow the relevant manufacturer's preparation instructions.

What sanding grit should you use after scraping?

There is no single grit that is right after every scraping job. Coarse abrasives remove material faster, while finer grades refine the finish. The starting point depends on how rough the prepared surface is and what needs to happen next.

Our P40-P320 sandpaper grit guide explains how the grit numbers relate to coarse removal, intermediate preparation and finer finishing. Browse Abrasives & Consumables for sanding products.

Do you need a sanding block?

A sanding block can improve control compared with simply holding an abrasive sheet in your fingers, especially when you want to spread pressure across an area or follow a particular surface profile.

For flat, curved and contoured work, see our sanding block guide, which compares a rigid-style fast-fit hand block, a flexible segmented block and a multi-profile six-piece kit.

Surface-preparation safety

Wear PPE suitable for the job and the material being removed. Old or unknown coatings can require additional assessment before they are disturbed, and dust or debris should be controlled appropriately. If you are unsure what a coating or substrate is, identify it before aggressive scraping or sanding.

A simple preparation sequence

1. Inspect the area and identify loose, flaking or raised material.
2. Choose a scraper width that suits the size and access of the area.
3. Remove only material that can be worked safely without damaging the substrate.
4. Use suitable abrasives to refine the prepared area.
5. Remove preparation debris and follow the coating manufacturer's instructions before the next stage.

Browse Painting & Decorating for scrapers, brushes and roller equipment, and Abrasives & Consumables for the sanding stage.