The importance of perfect cleaning cannot be over emphasized, since the efficiency of any operation depends on the adhesion of the deposited metal. Of the various processes formulated to give a clean surface suitable for plating, none is more important than the removal of grease, oil and soils left from machining, stamping, pressing or polishing. Plating on a dirty surface will result in peeling and/or blistering of the deposit.
The pre-treatment process prior to plating usually consists of hot alkaline cleaning – normally a hot soak cleaner followed by a hot electrolytic cleaner. After rinsing the articles to be plated are immersed in a dry acid salt to remove any oxide film that has formed during the cleaning stages. The articles are then rinsed again before being electroplated.