ISO 9001:2015 CERTIFIEDBarrel vs Rack Plating
Electroplating is a process that uses an electrical current to bond dissolved metal ions onto a substrate to form a thin protective or decorative coating to the surface of the substrate.
The two most common methods for electroplating parts are barrel plating and rack plating, both provided by Microfinish in St. Louis, Missouri.
Barrel plating, as you can imagine from the name, is performed using polypropylene barrels. Inside the barrels are cable danglers that conduct the electrical current for electroplating. Parts to be plated, are placed in a barrel which then rotates as they are submerged in the plating solution. Parts tumble or cascade, exposing the surfaces of all parts to the plating solution. Advantages to barrel plating include parts with configurations that don’t allow them to be hung on a fixture or rack. Barrel plating allows for bulk processing, so many parts can be placed in a barrel at once. This requires less labor as compared to rack plating, therefore it is usually less expensive. One disadvantage is, since this is a bulk process, 100% of the parts may not get coated. Flat parts lie on top of one another, or lodge in areas of the barrel, but the overall cost advantage greatly offsets the process limitations of barrel plating. Barrel plating typically is the best process for parts that are small and durable.
Rack plating is more labor intensive because each part must be attached to a rack using hooks, compression contacts or other methods. Rack plating is good for delicate parts that should not be tumbled since parts stay fixtured during the plating process. This method also is good for large parts that won’t fit in a barrel, and for parts where a high-quality/cosmetic finish is of utmost importance. The cost to build racks and the labor to rack the parts on the fixtures, are the main factors that make rack plating more expensive than barrel plating.
Both barrel and rack plating methods are used at our zinc plating facility. We can help you to understand the benefits and disadvantages to either one of these methods as they apply to your specific parts.
