The Differences Between Barrel and Rack Plating

Choosing the right electroplating method is essential for achieving optimal results and minimizing the risk of damage to the finished product. Two of the most commonly applied processes for plating multiple workpieces are barrel and rack plating. Each offers several advantages, as well as points the plater and customer must consider when determining the most appropriate method for their project.

What Is Barrel Plating?

As the name implies, barrel plating entails placing the parts inside a barrel typically constructed of polypropylene. The barrel contains center bars that conduct the electrical current. The barrel rotates slowly while immersed in the electrolytic plating solution. This causes the parts to tumble or “cascade,” which provides an even, uniform coating application. Typical barrel plating applications include enhancing corrosion protection, increasing aesthetic appeal and producing an engineering finish that protects the parts against wear and tear.

Barrel plating offers a cost-effective means of plating a high volume of small, durable parts such as stampings and fasteners. It also works well for plating parts of various shapes and sizes. Barrel plating requires a smaller investment in equipment and is less labor-intensive than rack plating, which ultimately results in a lower process cost to the customer. On the downside, most barrel plating techniques require a low electrical current, which can increase the time that the parts are exposed to the plating solution.

What Is Rack Plating?

Rack plating differs from barrel plating in that the parts are affixed to metal racks with screws, wires or spring fingers. This causes the parts to remain stationary upon immersion of the metal rack into the plating solution. Consequently, metal platers prefer rack plating for delicate parts that might not be able to withstand the tumbling or cascading action produced by barrel plating. Rack plating also works well for large or complex components.

In addition to affording increased protection against damage to parts, the rack process can plate contours and intricate shapes more efficiently. Rack plating is the preferred choice in industries where a high-quality finish is paramount such as military and defense, automotive, medical and electronics. Disadvantages of rack plating include the higher cost and increased labor requirements. In many cases, it may be necessary to design and manufacture a customized rack for specialized applications.

Both barrel and rack plating are compatible with a wide variety of metal finishing technologies such as zinc, tin, copper and nickel, as well as precious metals such as gold and silver.

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Contact Sharretts Plating to Learn More About Barrel and Rack Plating

SPC offers decades of barrel and rack plating experience, along with the expertise to help you select the right method for your metal finishing applications. Contact us to learn more today.