What is Brush Plating?
by Derek Vanek
Brush plating, or selective plating, is a method of electroplating on a localized area without the use of an immersion tank. It is primarily used for enhancing surfaces on OEM components, permanent repairs and salvaging worn or mis-machined parts. Although, originally conceived and developed by George Ixci in Paris, France in 1938, the technique has been engineered and enhanced by continuous research and development at SIFCO Applied Surface Concepts. The SIFCO Process® equipment is portable, enabling technicians to plate parts in place without disassembly, saving companies money and minimizing down time.
In a typical operation, the part is first masked and then a series of base material-specific preparatory steps are conducted to ensure an adherent deposit. The last step is the plating of the metal deposit to the desired thickness.
A portable power pack (rectifier) provides the direct current required for plating, anodizing and electropolishing. The power pack has two leads, one of which is connected to the plating tool and the other which is connected to the part being finished. The direct current supplied by the power pack is used in a circuit that’s completed when the plating tool is touching the work surface. A brush-plating power pack gives the operator the ability to control and monitor the voltage, amperage and ampere hours for a given job, as well as to change the polarity as required for each of the steps involved in the process.
Brush plating requires movement between the plating tool and the part. This can be accomplished by moving the plating tool over the part, by moving the part and keeping the plating tool stationery, or by moving both. Dedicated electrodes are used for each operation in the process to electrochemically prepare the part and then to plate the final deposit. The electrodes are covered with an absorbent material saturated with a solution and then applied to the part.
Brush plated surfaces provide a multitude of benefits, such as:
• Corrosion protection
• Improved wear resistance
• Improved solderability or brazing characteristics
• Decreased electrical contact resistance
• Galling prevention
• Serving as bearing surfaces