Out-of-Position GTAW Welding in a position other than fl at is called out-of-position welding. Small assemblies usually can be placed so the welding is done in the fl at position. Larger assemblies, which often cannot be moved, require the welder to weld out of position. See Figure 22-1. Many welder qualifi cation tests are performed on out-of-position joints. If a welder can make good welds out of position, he or she can also weld properly in the fl at welding position. Chapter 7 describes and illustrates the different welding positions. Welding in the Horizontal Welding Position The weld axis and weld face are horizontal or close to horizontal when making a weld in the horizontal position. Welding in the horizontal position can be more diffi cult than welding in the fl at position. Gravity pushes the molten weld pool down. This causes the weld bead to sag and not properly fi ll the joint. It is important to use the correct torch angles and techniques to obtain high- quality welds. Preparing to Weld Before beginning any welding, check that the equipment is assembled and set up correctly. Select and set the type and amount of current, the electrode type and diameter, and the type and amount of shielding gas you will use. Select the correct welding rod. Refer to Chapter 20 for more information. Pulsed GTAW may be used to make high- quality welds in out-of-position joints. The pulsed arc allows the weld pool to cool between pulses. Good penetration is still obtained. Pulsed GTAW is discussed in Chapter 19. Protective clothing worn for out-of-position welding is the same as for fl at welding. Wear a long-sleeved shirt with the collar buttoned. Wearing a welding cap is a good practice. A leather coat or cape is recommended for welding overhead. Safety glasses, a welding helmet, and thin leather gloves are required. Bare skin must be well protected from the arc and from falling molten metal. Holding the torch and starting an arc are the same as in fl at welding. Weld pools in out-of- position welding are kept the same size or slightly smaller than those used in fl at welding. The current setting on the machine can be reduced slightly. This keeps the weld pool smaller. However, penetration is shallower when the current is reduced. The electrode is held 1/16″–1/8″ (1.5 mm–3 mm) from the base metal. Typically, the electrode-to-workpiece distance is about equal to the diameter of the electrode. Fillet Weld Horizontal fi llet welds are very common. They are made on lap joints, inside corner joints, and T-joints. Figure 22-2 shows a welder making a fi llet weld in the horizontal welding position. When making horizontal fi llet welds, the travel angle is held at 15°–30°. The work angle is 45°. The torch is angled so the electrode points in the direction of travel. This is a push angle. Filler metal is held 15°–20° from the weld axis and in line with the axis of the weld. The torch and fi ller metal angles used to make a horizontal fi llet weld are shown in Figure 22-3. The torch is centered over the root of the weld but pointed more toward the vertical piece. This helps prevent undercutting. Filler metal is added to the upper leading edge of the weld pool. When Miller Electric Mfg. Co. Figure 22-1. GTAW being used to weld a V-groove butt joint on pipe. 324 Section 4 Gas Tungsten Arc Welding Copyright Goodheart-Willcox Co., Inc.