Welding in the Vertical Welding Position When vertical welding with the gas tungsten arc process, center the electrode over the root of the weld joint. Point the torch upward so it forms a push angle of 15°–30°. Figure 22-9 shows a welder welding a joint in the vertical position. Notice the angles of the torch and welding rod. Thicker metals are welded with the weld pool moving from the bottom of the joint toward the top. This is called uphill (vertically up) welding. Thin metals, 1/16″ (1.6 mm) or thinner, are welded using downhill (vertically down) welding. When welding downhill, the fi ller metal is added to the trailing edge, which is the top of the weld pool, or the side of the weld pool. Figure 22-10 shows the angles used to weld downhill. Fillet welds use a weld pool shaped like a C. This is the same as in fl at welding. Butt welds use the keyhole method to obtain full penetration. See Figure 22-11. 15°–20° 70°–75° 15°–20° Goodheart-Willcox Publishing Figure 22-9. A fillet weld on a lap joint being made uphill. The electrode is positioned with a push travel angle of about 15°–30°. It is pointing more at the surface than at the edge. Note that the welding rod is held at about 15°–20° to the weld axis. Goodheart-Willcox Publishing Figure 22-10. When welding downhill, the electrode is held in line with the weld axis with a 15°–20° travel angle. The welding rod is held at 15°–20° from the base metal. It may be added from the top or side. 328 Section 4 Gas Tungsten Arc Welding Copyright Goodheart-Willcox Co., Inc.