What is the essential difference between waterproof sandpaper and dry sandpaper? Is it really what it means literally? Why does dry sandpaper not use water, but waterproof sandpaper does?
Waterproof sandpaper has smaller gaps between sand grains, and the ground powder is also smaller. When used with water, the powder will flow out with the water, so it is best to use it with water. If waterproof sandpaper is used for dry grinding, the powder will remain in the gaps between the sand grains, making the surface of the sandpaper shiny and unable to achieve its original effect. Dry sandpaper is very convenient. The gaps between its sand grains are larger, and the powder is also larger. During the grinding process, the powder will fall off due to the large gaps, so it does not need to be used with water.
Dry sand is divided into the so-called red sand and white sand. The difference is that the former is not treated with anti-blocking coating. Waterproof sandpaper grinds slower but produces a smoother finish (the finer the water sandpaper, the slower it grinds and the smoother it produces, and it is often used for oil grinding of high-gloss products); dry sandpaper grinds faster but produces a coarser finish (the coarser the dry sandpaper, the faster it grinds and the coarser it produces, and generally sandpaper with a grit of less than 400 is used for white wood grinding, and sandpaper with a grit of 400-800 is used for oil grinding of parts).
Waterproof sandpaper is usually used for grinding under water conditions, so there is less dust and better working conditions. Although dry sandpaper has the characteristics of anti-blocking, anti-static, good flexibility and high wear resistance, it is heavily polluted by dust and requires appropriate protective equipment during operation (but it is also acceptable to face the strong performance of dry sandpaper).
