Cutting compound is a paste-like substance that contains abrasive particles. It is often used to remove damaged paint from an automobile. This compound is typically used on cars that don’t have any type of clear protective coating layered on top of the paint.
As with sandpaper and other abrasive materials, cutting compound comes in a variety of different grit sizes. The coarser grit is used for rough, heavy work, such as removing a layer of paint from a large area or smoothing a deep scratch. The finer grit is used when there is less of a need to remove a lot of old pain, and to achieve a more finished, polished look. Often a job will be started with coarse cutting compound and finished with some that is very fine.
Cutting compound is often used to restore the appearance of auto paint that has become oxidized. It is applied like paste, but, when rubbed, the abrasive particles will cut into the surface of the paint. This allows the top layer of paint to be removed, exposing the under layer. When paint is oxidized the outer surface of the paint will have a faded, weathered look, but underneath the oxidation the paint looks like new. Once the outer layer has been cut through and rubbed away, the paint that is left matches the original color of the car.
Many scratches can also be removed through the use of cutting compound. The scratched area is rubbed with the compound until the paint around the scratch is smooth enough that it all looks the same. This usually works well on surface scratches but is generally not successful on very deep scratches, since too much of the paint would have to be removed to achieve any kind of a result. In such cases the area may be smoothed out through the use of cutting compound, but new paint will have to be applied to completely hide the scratch.
It is important not to overuse cutting compound. If too much is used at once, or if it is rubbed in too hard, it is possible to strip all of the paint from the area. This leaves the bare metal of the car exposed, making it unattractive and vulnerable to damage from the weather.
After paint has been removed, the newly exposed area must be protected in order to prevent additional damage. The area should be waxed with a good-quality wax. It can then be polished so that the area looks and acts like new.