finishing

Covering or coating placed over the surface of a material in order to protect it and/or make it look better. Finishes can be temporary or permanent. Temporary finishes have to be redone after a period of time. They include finishes such as oiling and greasing on metals, and waxing and polishing on timbers. Finishes such as staining are semipermanent. There are many permanent finishes. Timbers can be varnished, lacquered, or painted. They can be covered with a veneer, or engraved. Metals can also be painted, engraved, etched, electroplated (galvanized), enamelled, and dip-coated in plastic.

Before a material is covered, its surface has to be prepared so that the covering does not fall off. First, the surface has to be treated with an abrasive to smooth any rough edges and to create grooves to help the covering to stick better. Then the surface needs to be washed to remove dirt, and cleaned with a degreasing agent (turpentine or white spirit) to remove any oil or grease. For some finishes a primer or undercoat is added before the finish is put on.