Profile: Sulzer Metco Coatings Ltd. specializes in offering coating services. The electric arc wire spray process uses two metallic wires, usually of the same composition, as the coating feedstock. The two wires are electrically charged with opposing polarity and are fed into the arc gun at matched, controlled speeds. When the wires are brought together at the contact point, the opposing charges on the wires create enough heat to continuously melt the tips of the wires. Compressed air is used to atomize the now molten material and accelerate it onto the workpiece surface to form the coating. The HVOF (high velocity oxygen fuel spraying) liquid fuel uses an oxygen-kerosene mixture. The coating material, in powdered form, is fed axially through the gun, generally using nitrogen as a carrier gas. The fuel is thoroughly mixed with oxygen within the gun and the mixture is then ejected from a nozzle and ignited outside the gun. The ignited gases surround and uniformly heat the powdered spray material as it exits the gun and is propelled to the workpiece surface.