Nickel Plating


Many pinfire revolvers were nickel plated for decoration and enhanced protection against corrosion. Because the art of plating was not very advanced, the nickel layer was easily dislodged. As can be seen in the pictures below the nickel layer has virtually disappeared on the barrel of a 5 mm pinfire revolver.

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In most cases I will retain the original nickel layer but in this case only about 5% percent was retained so I decided to re nickel the barrel. To do so first all grease, corrosion and residual nickel plating had to be removed. All surface exposed to the plating solution will be covered with a layer of nickel. This is not wanted on threaded parts so these must be shielded. Since the plating solution works best at a temperature between 20o(C) and 50o(C) I decided to seal all threading using silicone sealant instead of wax.

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The final result depends on the preparation of the surface to be plated. Plating will not cover any scratches, dents or pitting so the surface must be as smooth as possible but care has to be taken that all markings and engravings remain undamaged. For maximal adhesion of the plating it is vital to clear the surface of grease and oxidation. To achieve this, the surface has to be polished with pumice powder using an old toothbrush.
For plating nickel anodes were used made from strips of nickel mesh used in rotary printing.

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The plating bath used consists of Nickel sulfate ( NiSO4·6H2O, 150 g/l ), Nickel chloride ( NiCl2·6H2O, 60 g/l ) and Boric acid ( B(OH)3, 40 g/l ).
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Current was obtained from a laboratory power supply set at about 1.5V. In order to maintain the right temperature a plastic container is placed as a double boiler in a temperature controlled bath of an ultrasonic cleaner. The temperature is set at 40o(C); the max. current is set at 300mA resulting in a voltage of 1.2V. For smaller items it is advisable to reduce the current. This slows the process and results in a better finish.

After 8 hours of plating the barrel was rinsed in tap water, lightly polished and oiled.

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For smaller items a simple plating setup is sufficient. In this case a jar was lined with nickel mesh and filled with preheated plating solution. The nickel mesh (anode) was connected to the (-) of the laboratory power supply, the object to be plated (cathode) was connected directly to the (+) of the power supply. Since this object (extractor pin) is very small current was reduced to 0.05A.