Sandpaper uses paper or cloth as the base material with an abrasive bonded to the surface. It reduces and smooths the surfaces and corners of timber and plastic, etc. by rubbing.
The term “sandpaper” can refer to sandpaper, emery cloth or waterproof “wet and dry” but it generally refers to sandpaper. One of its principle features is that it is made of craft paper or other non-water resistant paper and it can be cut or folded to fit the shape of the item to be sanded. When the abrasive material falls off, it is less effective and is replaced. There is no established method but when working a flat surface, it is easier to get an even finish if the sandpaper is wrapped around a piece of wood which is easy to hold in the hand. For more intricate work, it can be pasted around a rod and for corners and curved surfaces, the shape of the object holding the sandpaper can work to your advantage. There are also commercially available tools called hand sanders and sandpaper holders that are used to hold the sandpaper. When working on small items, sandpaper can be secured to a flat board with thumbtacks and it is easier to rub the object against the board.
The size of the abrasive grain is known as granularity and the roughness is expressed in grit size. The coarsest sandpaper is at the 30 end of the scale and becomes progressively finer through 40, 60, 80, 100, 120, 150, 180 and 240. As a general guide, sandpaper under 100 is coarse and is used to remove soiled surfaces. 100 to 200 is used to obtain a level surface. 200 to 400 is used for smoothing but if an even smoother finish is required, 400 or higher is used. In this way, the work of sanding a rough item is done gradually in three to four stages. When cutting sandpaper, turn it over to expose the backing and use a ruler to tear it off rather than scissors or a cutter which might get damaged by the grain. Sandpaper can be obtained from any home center or hardware store.
- The structure of sandpaper