Plating Coverage using Internal Anodes

Electroless Plating Alternative

When electroless plating is not an option and the plating thicknesses of electrolytic coatings are of high importance on the internal surfaces of a part such as cavities/bores, cylinders or the inside of accumulators, the use of an internal anodes is the only alternative to achieve complete and uniform coverage on the interior of components.

Without the use of a supplementary electrically conductive anode you can typically expect a plating thickness ratio of 1:5 from internal to external surfaces on a cavity as small as 70mm in length. This ratio will increase if the cavity is longer, and at worst case could result in no coatings being deposited. Therefore the internal anode will alter the current distribution in electroplating and give a more uniform thickness throughout a cavity or interior surface.

Paramount Metal Finishing has decades of experience in designing the necessary tooling to maximize the properties of using of internal anodes. These fixtures will ensure a smooth, homogenous internal coating, similar in thickness, performance and appearance to that of external plating deposits.

Internal anode plating is a unique way of maximizing corrosion protection on the inside of parts, especially items of intricate designs and configurations such as pipes, tubes, chassis and cup shaped items.

Paramount Metal Finishing can accommodate internal anode plating to a wide range of complex parts with zinc plating for parts up to 11 feet in length; zinc nickel plating, bright tin plating for parts up to 9 feet long.

Smaller size projects for plating of gold, silver and indium plating can be performed as well with internal anode technology. Paramount also offers complete and uniform coverage utilizing electroless nickel plating (ASTM B733 and AMS-C-26074) for parts up to 9 feet in length.

Electrolytic Zinc plating ASTM B633, Zinc Nickel AMS 2417, ASTM B841