Wire arc spray is a form of thermal spraying where two consumable metal wires are fed independently into the spray gun, with an arc generated between them. The heat from this arc melts the incoming wire, which is then entrained in an air jet from the gun. This entrained molten feedstock is then deposited onto a substrate with the help of compressed air. This process is commonly used for metallic, heavy coatings. It covers applications for welded tube seams, piston rings, capacitors, varistors, boiler walls and large infrastructure.