Carbon arc gouging rod or graphite rod is to use as an electrode, an arc is generated between the workpiece, the metal is molten, and the molten metal The method of addition of a surface machining grooves blowing with compressed air. Gouging, eliminating defects in welds and back root mainly used in welding production. Carbon arc gouging has the following features: (1) handmade carbon arc gouging, flexibility can be all-position operation. Reachability, very easy. (2) removing a defect of the weld, in the arc can be clearly observed that the shape and depth of the defect. (3) low noise, high efficiency. Automatic carbon arc air gouging with high accuracy, reduce labor intensity. The drawback is that the carbon arc gouging: carbon arc smoke, dust, pollution, and the arc radiation, improper operation prone to channel by carbon.