Is it Sandpaper or Coated Abrasives?

Whether you call it sandpaper or a coated adbrasive , the purpose it provides remains the same.

Sanding is generally a operation that smooths the wood after it has been cut or shaped with various wood tools.

There are a vast amount of grit sizes that are use to sand the wood to whatever degree of smoothness we desire.

The lower the grit number the coarser the paper, thus making a rougher finished, The opposite is true when the number is higher, the higher the number the finer the grit, thus smoother work is achieved.

There are basically four principle types of abrasives coatings that is applied to the backing, be it paper or cloth.

These are garnet, flint, aluminum oxide, and silicon carbide. Flint in real term is actually quartz and because it lacks toughness it has little value in woodworking. Although it is cheaper than the others it can cost more to use because of its grit life.

Garnet is a reddish-brown mineral that is harder than flint and is a very good abrasive and is widely use in woodworking.

Aluminum oxide and silicon carbide are both man made and very hard. It has a faster cutting acton and a longer life than the first two abrasives.

The backing, paper or cloth holds the abrasives grains and is known as either open or closed coat, The open coat leaves space between the particles so that only 50 to 70 percent of the surface is covered.

The closed coat has the particles more densely packed together covering the entire surface of the backing. This type of sandpaper is a fast cutting but with the disadvanage of clogging while using with soft materials.

In general use a open coat with soft materials or wood with a lot of resin and a closed coated for general sanding.

There are many different methods of sanding and different sand paper sizes and grit for each.There is hand sanding and there is sanding that is done by machinery either hand helded or stationary



Grit and their uses

40-60 Sands - very course and will rough up the surface.Good to start out on rough surfaces.

80-120 Sands - medium sand that will remove small marks and imperfections.

150-180 Sands - Puts a final sanding on the surface before finishing the wood.

220-240 Sands - Very fine sanding, use for between coats of sealer or stains.

280-320 Sands - Extra fine sanding, use for removing marks or dust spots between finish coats.

360-600 Sands - Super fine sanding, use for very fine sanding to remove blemishes and scratches.



One final note always use the proper sanding paper for the particular job at hand and always , always wear safety glasses and a dust mask.

This will help keep dust particles from out of your eyes and lungs which can be very unpleasant.


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