Decoppering Gun Tubes Using Selective Electropolishing.

The primary purpose of this paper is to demonstrate an alternative decoppering technique of selective electropolishing, which will enable the cleaning of copper-fouled barrels in a reasonable amount of time within a maintenance schedule. A description of the electropolishing process is elaborated upon as well as the more traditional decoppering mechanisms of CuPb and CuBiSn alloying. Metallurgical aspects of the current decoppering mechanisms are presented in the spirit of providing guidance for developing a more suitable permanent decoppering solution. Two coppered regenerative liquid propellant gun RLPG barrels were first star-gaged and bore-scoped to determine the baseline. Electropolishing was performed on each, after which they were star-gaged and bore-scoped to enable a comparison. Details of the process are included, and the results show that this procedure can indeed clean a copper-fouled barrel without detrimental removal of base material.