the higher conductivity is typically several microns thick or more the presence of a coating having a higher thermal conductivity than the piston material on the inside of the gallery wall will distribute the heat quickly 360 degrees around the gallery increasing the effective path by which heat is conducted to the oil this provides more effective cooling of the piston dome and the top ring groove which will improve the durability of those regions the coating having the higher thermal conductivity is typically copper although another material having a higher conductivity than the piston material could also be used the coating having the higher thermal conductivity can be deposited on the oil gallery wall by electroless plating either autocatalytic or immersion alternatively an electroplating process can be used in one embodiment the material having the higher thermal conductivity can be plated onto aluminum or steel by first degreasing and cleaning the surface to be plated using trichloroethylene methylene chloride or other solvents for aluminum pistons a solution containing copper sulfate perchloric acid and ammonium oxalate is degassed with nitrogen or ultrasonic energy and poured into the piston such that it is in contact with the surfaces to be plated plating kinetics with this type of solution are described in u201c influence of perchloric acid on the kinetics of immersion plating of copper onto aluminum u201d hydrometallurgy 61 2001 1 11 mandakini et al and u201c study of morphology of copper deposited onto aluminium by immersion plating from an oxalate bath containing perchloric acid u201d minerals engineering 16 2003.