Electrolytic Cleaning

It is effective as a final cleaning process for eliminating oil and grease from machined surfaces while extreme cleanliness is required. This is almost always used for final cleaning of steel parts prior to electroplating.

In electrolytic cleaning, an alkaline cleaning solution is utilized with electric current passing through the bath in which the part to be cleaned is one electrode. It causes the emission of oxygen at the hydrogen and positive pole at the negative pole. The material from which the part is built and the cleaning action desired determine whether the part must be made the anode or cathode. Parts from soft metals such as zinc, lead and tin ought to be necessarily. At the cathode, a greater amount of gas is liberated than at the anode, and the hydrogen has some decreasing action on oxides present. The electrolytic action breaks up the oil film adhering to the metal surface and results in chemically clean surface appropriate for plating.

Chlorides must be carefully avoided and the soap content must be low or excessive foaming with danger of an explosion might result.