worksmarterdiy - HAND SANDING | SILICON CARBIDE VS ALUMINIUM OXIDE

Sandpaper, decorator’s mate, or if you prefer, hand sanding abrasive, they all do the same thing right? Wrong! With every sanding job there is an abrasive that is best suited to the task in hand.

Here we tackle some of the main hand sanding abrasives available and guide you through the pros and cons and the jobs they are best suited to in order to help you decide which you need.

How do abrasives work?

There are many different types of abrasives, with different grits and backing materials, but most are produced in the same way.

The abrasive grains or grit, is produced by heating or chemically treating minerals which produce a hard material that is particularly good for abrading surfaces, such as wood or metal.

Once treated, these minerals are crushed and sifted to create varying grit sizes with the finer grain sizes producing a finer finish.

Grain coat types

There are two types of coats available, open coat and closed coat. An open coat paper means there are less abrasive grains bonded to the backing surface. They provide a slower cut and are best suited to sanding naturally soft materials.

If the backing sheet is 100 percent covered by the grit, then the coat is closed, which makes it a strong abrasive that will achieve a finer finish.

Friability

Wear and tear is an important factor to consider when choosing an abrasive. This is called the friability of an abrasive, when the application of heat or pressure breaks down the abrasive grains.

If an abrasive is highly friable, it means it breaks down easily creating new sharp surfaces that abrade, which make them last longer.

Abrasives with low friability can dull much quicker.

Aluminium oxide abrasives

One of the cheapest and most popular abrasive materials is aluminium oxide paper. It is an all round general abrasive for woodworking and is an industry standard due to the many uses it is suitable for, including use on bare wood, painted surfaces or metal.

Silicon Carbide abrasives

Often used for finishing, silicon carbide papers deliver consistent results, but can be more expensive than aluminium oxide papers. It makes it a great choice when abrading hard surfaces like wood finishes, paint, plastic and metal.

Silicon carbide sandpaper also removes material without building heat.

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