With plasma arc gouging an operator can achieve a smooth, clean, consistent groove, and by using different gases can help optimize gouge quality and surface conditions. With carbon arc gouging, gouge quality can be hard to control, and carbon deposits, or inclusions, may be added to the base metal. The plasma gouging process is relatively quiet and smoke free when compared to the noise and excessive smoke fumes produced by arc carbon gouging. Plasma arc gouging can be used on mild steel, stainless steel, aluminum, and almost any ferrous or nonferrous alloy. Carbon arc gouging can be used on mild steel, cast iron, nickel alloys, copper, and aluminum. A plasma cutting system is more expensive, and has a lower metal removal rate than that of air carbon arc gouging. The practice and skill level required to master plasma gouging is also higher than that of carbon arc gouging.