Electroplating Activation and Agitation
Two areas often overlooked when electroplating are activation and agitation. Both activation and agitation are a key part of the processes and shouldn’t be overlooked. Simply put, activation is just the removal of an oxide layer that forms on the surface of the metal. Most metals under normal atmospheric conditions undergo a chemical reaction with the oxygen and water in the air to form a layer of metal oxides. Sometimes a layer of metal oxide just a few atoms thick is enough to cause problems for your project. The benefit of activation is that it not only removes this oxide layer, but it also removes any salts, soaps, or alkaline cleaning products left on the surface of the metal. If these products are not removed, they will cause staining, skip plating, or even delamination and blistering. Soft metals such as copper, bronze, and brass are most easily activated with a simple acid pickle. Harder metals such as stainless steel, nickel, and chrome, can also be activated with an acid pickle. However, the pickle will need a higher concentration and the immersion time will be longer. Another way to activate some of the more difficult metals is to reverse the polarity of the current for a few seconds, less than 30 seconds, just prior to plating. Remember wash well after pickling.
Another often under-appreciated step in electroplating is agitation. There is a misconception, especially among home platters, that this step can be optional especially for small parts. However, that is not true. The better the agitation, the better the finish is going to be. There are several methods for agitation. Air is the cheapest. A simple air pump like those found in fish tank is often sufficient agitation. Next to air is mechanical agitation, which can be as simple as stirring the electrolyte while plating. This is a particularly useful method for fine delicate work, but stirring the electrolyte for a long period of time may be impractical for larger thicker pieces. You may want to consider a small electric motor.
Don’t neglect simple details like activation and agitation when electroplating if you want a spectacular finish. Contact us at 1-888-257-0880 for more information about how we can help you with your electroplating needs.