Electroplating involves the coating of an electrically conductive object with a layer of metal using electrical current. Usually, the process is used to deposit an adherent surface layer of a metal having some desired property onto a substrate lacking that property. It is also used to build up thickness on undersized parts. The process used in electroplating is called electrodeposition and is analogous to a galvanic or electrochemical cell acting in reverse. The part to be plated is the cathode of the circuit while anode is made of the metal to be plated on the part. Both of these components are immersed into a solution containing one or more metal salts as well as other ions that permit the flow of electricity. A rectifier supplies a direct current to the cathode causing the metal ions in solution to lose their charge and plate out on the cathode. As the electrical current flows through the circuit, the anode slowly dissolves and replenishes the ions in the bath.