Definition - What does Rack Plating mean?
Rack plating is a method used to electroplate brittle, large and complex parts that are difficult to plate using other processes. The parts are mounted to a fixture or jig, known as a "rack" and then immersed in a plating solution bath. Metal hooks are used to offer the required electrical contact while holding the parts in place on the rack. uniform thickness distribution is achieved since the rack can hold various parts which are plated at the same time.
Corrosionpedia explains Rack Plating
Electroplating is performed on parts with complex geometry that require unique finishing. To achieve this while reducing time and cost, one can use rack plating since it can hold multiple parts, as opposed to submerging individual parts in a bath. The fixture or jig is metallic in nature, so that it provides a complete galvanic cell circuit for electroplating. Screws, wires and pins are used to provide the least electrical contact to provide current for the plating process, providing high-quality finishing for intricate contours and delicate parts.
During the rack plating process, scratches and damage are avoided by spacing the parts well on the jig. However, this is a labor-intensive and expensive method, as it takes time to hang the parts. Therefore, if the parts are not fit to undergo barrel plating, the only forthright solution would be to opt for rack plating. It is common in zinc and aluminum electroplating, likewise, nickel and chrome are the most used plating solutions in this process. Before settling on this method, one should consider the shape, quantity and size of the parts.