195 Chapter 8 Gas Metal and Flux Cored Arc Welding Flux cored arc welding (FCAW) is very similar to gas metal arc welding, but unlike GMAW, it uses a fl ux- fi lled welding wire. GMAW has a wide range of applications due to sev- eral factors. The continuous development and refi ne- ment of constant voltage power sources and wire feed- ers has made GMAW more effective to use. GMAW is easy to learn, especially if a welder has already learned a different welding process. GMAW equipment is rel- atively low in cost. Also, GMAW deposits more weld metal in lb/hr (kg/hr) than the SMAW and GTAW pro- cesses. The low purchase cost, the ability to weld con- tinuously, and the ability to deposit weld metal faster make GMAW an attractive choice for welding. GMAW can produce high-quality welds on most metals commonly used in manufacturing, including carbon and alloy steels, stainless steels, aluminum, magnesium, copper, and others. GMAW can also be performed easily in all welding positions. GMAW is performed in almost all industries and is used in most robotic arc welding applications. It is also widely used on farm and home applications. FCAW is a popular welding method that is used in many industries, including structural welding. It has the advantages of both GMAW and SMAW. Like GMAW, FCAW includes the ability to weld continu- ously and to deposit weld metal faster. FCAW and GMAW are also easy processes to learn. Like SMAW, FCAW includes the addition of alloying and fl uxing elements in the electrode. ESAB Welding and Cutting Products Learning Objectives After studying this chapter, you will be able to: • Contrast GMAW metal transfer methods, considering arc characteristics, weld characteristics, and out-of-position welds. • Select the proper arc welding machine, wire feeder, shielding gas, fl ow rate, contact tip, nozzle size, and welding wire type to produce an acceptable weld. • Identify the different shielding gases used for GMAW and explain how they affect the shape and penetration of the completed welds. • Properly assemble and adjust all the equipment required to produce an acceptable weld using the GMAW and FCAW processes. • Make acceptable welds on all types of joints in all positions using GMAW. • Make acceptable welds on all types of joints in the fl at and horizontal positions using FCAW. • Identify potential safety hazards associated with the GMAW and FCAW processes and describe proper safety procedures. T he gas metal arc welding (GMAW) process uses a solid or metal cored welding wire that is continuously fed into the weld pool. The weld- ing wire is consumed and becomes the fi ller metal.