A Guide to Metal vs Wood Sandpaper

A pile of assorted sandpaper scraps.

Sandpaper can be used on various materials including wood and metal. It’s used to scrub away any imperfections on the surface of a material, such as old paint, and to smooth either the edges or the flat surface.

There are many different sizes—or grits—according to the material you want it for and for what type of work you need it. The grit available ranges from very coarse (used commonly to remove rust on rough metal materials) up to very fine grits (used more often for finishing details on delicate materials such as varnish).

Obviously, we are referring more to commercial sandpaper, used in home jobs, because industrial sandpaper is far more expensive and is made out of better materials to suit the industrial sphere.

Nowadays sandpaper can be found in various shapes, such as sheets, discs, belts, etc., since certain power tools will use a special type of shape unique to them.

Backing Material

There are three types of backing material for sandpaper: ordinary paper, waterproof paper, and cloth. Ordinary paper is relatively very cheap compared to other types of backing and it is manufactured for hand use rather than use with power tools.

Waterproof paper, as the name declares, is water-resistant and is intended for when you are using lubricant. The cloth-based material is used when you need a certain amount of flexibility for your work.


When you are going to use sandpaper it is advisable to use a sanding block. A sanding block is normally used for tougher jobs so that you can wrap a piece of sandpaper around it to get a greater grip.

Alternatively, you should use your hand more often with fine sandpaper because you can more easily manipulate your hand to reach difficult areas in order to complete the finishing touches.

Using Sandpaper On Metal

When using sandpaper on metal materials, it is a good idea to use closed-coated sandpaper because it is designed specifically for metal surfaces. One drawback with closed-coated sandpaper, however, is that it clogs very easily with dust.

You can use either aluminum oxide sandpaper or silicon carbide sandpaper. The former tends to last longer than the latter, but silicon carbide based sandpapers are suitable for cutting harder materials, so it will be able to handle the job, no matter what.

Using Sandpaper On Wood

Prior to sanding a wooden surface, check carefully for any imperfections and remove any rough spots or planer marks. The latter is very important because even though imperfections may not seem very worrying on rough wood, once the wood is finished, the imperfections will pretty much be the center of attention.

Different types of wood require different types of sandpaper. The object of sanding wood is to smooth it as much as possible, so on small edges and in small areas, it’s better to use your hand rather than a power tool. Also, always remember to sand in the direction of the grain for best results.