Sandpaper: Numbering According To Your Applications

Whether you want to keep your furniture in good condition or renew your car paint, you must know how to do manual sanding, which can become a true art for DIY enthusiasts and professionals. In this sense, it is very important to learn more about the types of sandpaper and their different uses.

The choice of sandpaper can be confusing if you want to know how to sand a wall or any other type of surface. For this reason, we mention everything you need to know about sandpaper so that you can choose the type that best suits your needs.

What are the types of grit of sandpaper?


The higher the number of the paper, the finer the grain, so a sandpaper with a 200-grit numbering is 2 times finer than a 100-grit sandpaper. In this sense, the numbering expresses the density of the grain . Therefore, the higher the number, the less abrasive the paper will be.

The extra coarse grain is usually the one with a numbering of 16 to 40 and is useful in a large number of jobs, such as for sanding wood, removing layers of paint or varnish before doing a more delicate job and even for sanding walls. On the other hand, the coarse grain is numbered from 50 to 60 and, in general, this type of paper serves as sandpaper for metal, mainly in exterior structures, such as fences, window frames, etc.



Among the sandpaper for wood, the most used option is the medium grain, between 80 and 100, which is suitable for correcting small flaws. There is also the fine or fine medium grain, which has a numbering of 120 to 150 and is appropriate for the last stages of work. In the same way, to polish wood and obtain a smooth surface to the touch, then you must use very fine-grained sandpaper , which is the one between 180 and 240, suitable for the last sanding before painting.

Finally, there is the extra-fine grain that has a numbering of 280 or more, which is mainly intended to make small corrections, since it is a low abrasive sandpaper.


The importance of defining the desired finish


All types of sandpaper are very useful depending on the finish you want. For example, to sand a piece of furniture before applying the varnish, a 180-grit sandpaper is appropriate. On the other hand, if you are making furniture with raw wooden boards , then you should start with a sandpaper with a thicker grain, such as 80 When finished, you can use a 240 grit sandpaper for the most delicate finishes.

On the other hand, it is important to mention that, whether it is paper for manual use or sheets for electric sanders , the grain is always expressed in the same way. The only thing that changes is the durability of the grain depending on the support and the quality of the manufacturer.

The different sandpaper supports


Many people do not usually take this aspect into account, but it is important to specify on what type of support the abrasive is adhered, since this could define its useful life. In this sense, sandpaper for manual use is usually made of paper and is used mainly for precision work , where it is required to sand a small or delicate surface.

Sander pads have a backing made of abrasive canvas or canvas, which is resistant to scratches, friction, and high temperatures. Therefore, it is a more resistant sandpaper, suitable for working on large surfaces. Regarding the presentation of sandpaper, it is available in discs, sheets, rolls, strips and even tips. The latter is a drill sandpaper that comes in different shapes to easily enter very tight places.

Abrasives that make up the sanding sheets


There are three main types of sandpaper, among which flint stands out, which represents the popular sandpaper that is normally used in polishing wood. In the same way, it is possible to use it with an electric sandpaper to polish varnishes or plasters.

On the other hand, there is corundum on paper or canvas, made up of a crystallized oxide of alumina, suitable for sanding very hard wood or paintings that are very old. In addition, it is useful for easily removing varnishes and sealants. Corundum sandpaper is therefore suitable for heavy duty applications.



Also, there is the emery cloth, which is suitable for rusty metals, uneven and curved surfaces. It can also provide a long service life as it typically offers a coarse grain that requires greater strength to optimally sand rustic surfaces. As for the manufacture, the emery cloth is made with a mixture of minerals that have been fixed on canvas.

Finally, it is possible to find a water-based sandpaper, made with abrasive products that can resist contact with liquids. It is generally used on metal parts, for example when repairing the surface of a car.

The origin of sandpaper


The earliest sandpaper prototypes date back to the 12th century in China. At this time, a parchment presentation was used that was composed mainly of seeds, grains of sand and fragments of seashells. The version of sandpaper that we know today was developed in 1833 by John Oakey, who at his company created gluing and manufacturing techniques to compose sandpaper.

Finally, we can say that sanding is one of the most important DIY processes, but to achieve a surface without roughness or with specific textures, you have to know how to select the right sandpaper for each need.

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