Abrasives
In construction and home repair, abrasives are used to prepare a surface for other applications. In some cases the goal is to smooth and polish that surface; while in other cases, the goal is to roughen surfaces in preparation for the application of glue or other adhesives.Forms and Functions of Abrasives
The type of abrasive one might need depends, of course, on the task at hand. The most commonly used abrasives include: garnet, a natural mineral which is generally used when giving wood a fine finish; aluminum oxide, a sturdy, widely-used synthetic mineral that is functional enough to be effective on both wooden and metallic surfaces; and silicon carbide, a mineral suited for use on a variety of surfaces including wood, metal, and even plastics.
A numerical scale is used to refer to the number of abrasive particles that can pass through a specifically sized mesh screen…this number signifies the “grit” of the abrasive (higher number grit producing a smooth texture to the surface being worked on; lower number grit giving a rougher texture).
Grit from 40-60 is considered to be of coarse grade; 80-150 is designated as medium grade; 180-220 is fine; and anything over 240 is considered very fine grade.