xvi Selecting the Electrode Wire ............236 Welding Machine Settings ...............240 Preparing the Base Metal ................241 Safety Precautions ...........................242 Shutting Down a GMAW/FCAW Station ..........................................242 Chapter 17 GMAW and FCAW: Flat Welding Position ...................247 Gas Metal Arc and Flux Cored Arc Welding Principles ..................248 Laying a Weld Bead .........................250 Making a Fillet Weld .........................254 Welding a Butt Joint .........................256 Welding Aluminum ...........................258 Weld Defects ....................................259 Chapter 18 GMAW: Horizontal, Vertical, and Overhead Welding Positions .......263 Out-of-Position GMAW and FCAW ....................................264 Welding in the Horizontal Welding Position ...........................264 Welding in the Vertical Welding Position ...........................268 Welding in the Overhead Welding Position ...........................271 Section 4 Gas Tungsten Arc Welding..............................276 Chapter 19 GTAW: Equipment and Supplies ......................................277 Technical Terms ...............................278 Gas Tungsten Arc Welding Principles ......................................278 GTAW Equipment ............................278 GTAW Machine ................................278 Torches ............................................282 Cables and Hoses............................284 Shielding Gases ...............................284 Regulators and Flowmeters .............284 Remote Current Control ...................284 Protective Equipment .......................287 Chapter 20 GTAW: Equipment Assembly and Adjustment ...........................291 Equipment Assembly .......................292 Welding Machine Settings ...............294 Selecting and Preparing the Electrode ................................296 Selecting Filler Metal .......................301 Preparing Metal for Welding .............301 Chapter 21 GTAW: Flat Welding Position .......305 Gas Tungsten Arc Welding Principles ......................................306 Welding a Bead on Plate .................308 Welding without Filler Metals ...........311 Fillet Welding a Lap Joint .................313 Welding Inside Corner and T-Joints ..................................315 Welding Butt Joints ..........................316 Welding Other Metals ......................317 Weld Defects ....................................318 Chapter 22 GTAW: Horizontal, Vertical, and Overhead Welding Positions .......323 Out-of-Position GTAW ......................324 Welding in the Horizontal Welding Position ...........................324 Welding in the Vertical Welding Position ...........................328 Welding in the Overhead Welding Position ...........................329 Welding Other Metals ......................331