Polishing compound

Also called buffing compound.

Polishing compound is a liquid or paste that contains a very fine grit. You rub it on a surface to polish it to a gloss.

Polishing compounds are available in several grades of fineness, each producing a glossier finish. Some, especially the marine grades for fiberglass boats, also contain waxes and other materials. Polishing compounds for machine parts or glass do not.

A polishing compound on its own can be used to remove oxidation from the surface of aged gelcoat. Coarser grades of compound will remove serious oxidation and finer grades will work for light oxidaton. You can also use polishing compound to polish out fine scratches or remove stains that won't come out with soap and water. When used as a final polish for gelcoat repairs, fine polishing compounds will bring the sanded repair patch to the same gloss as the original gelcoat.

Marine grade compounds are available at most marine supply shops. There are also compounds available in auto finishing shops.