In the twin wire arc system, two wires (with opposite polarity) are electrically charged and fed into the gun until contact is made at the nozzle. Generally, anywhere from 18 to 40 volts are applied across the wires to initiate melting of the tips. At this point, an atomizing gas propels the molten particles onto the substrate. This system allows thick coatings to be applied, which is useful in reclamation and atmospheric corrosion protection applications.