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Old 09-20-2009, 04:16 AM
john traveler john traveler is offline
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Ammonia will dissolve both nickel and copper. In dilute solutions this is a very slow process, but in hot, concentrated solutions, it is rapid and aggressive. Hot ammonia solutions are even corrosive to most stainless steel alloys.

In the old days (the first half of the 20th century) 28% ammonia solutions were commonly used to clean rifle bores fouled with cupro-nickel bullet jackets. This was in the days before guilding metal alloys were developed for bullet jackets. Excessive exposure to this aggressive bore cleaning solvent was also known to pit the bore.

The more readily available copper and nickel strippers include ammonium persulphate and ferric oxide. Both materials are commonly used to etch electronic circuit boards. Radio Shack did (or used to) sell home printed circuit board etching kits that included packets of ammonium persulphate crystals (white color) or ferric oxide crystals (rusty red color) with a plastic tray and instructions. A word of caution: excessive immersion is likely to pit the gun steel.

The best process, and the one least likely to damage the gun steel, is to use reverse electroplating to remove the nickel plating. This is relatively easy to do at home if you have a battery charger or variable dc power supply, a plastic or glass container, and access to enough nickel plating solution to immerse the gun. Plating shops often have friendly workers on the night shift and will give you a couple quarts of plating solution for the asking. The reverse plating is done by connecting the object to be plated (a scrap sheet of copper) to the negative terminal, and the object to be stripped (the gun frame) to the positive terminal. Low current densities (0.25 to 0.5 ampere) is best. Higher current density will strip faster, but tends to bubble the solution, and can make the stripping uneven. This is exactly what the gun refinishing shops do to strip nickel finish.
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