Exercise 22-4 Making a Vertical Fillet Weld 1. Obtain two pieces of carbon steel measuring 3/16″ × 3″ × 6″ (5 mm × 75 mm × 150 mm). 2. Clean one long edge on one piece and one face on the other piece. 3. Set up the welding station for welding carbon steel. 4. Tack weld the two pieces together to form a T-joint. Use a welding positioner to hold them in the vertical position. 5. Weld both sides of the T-joint uphill. Each completed bead should be a 3/16″ fillet weld. This will require three stringer bead passes or one stringer bead pass and one weave bead pass. Do not let the weld pool get too large, or it will sag. Inspection: The completed weld should be of high quality. The ripples should be evenly spaced, and the completed weld bead should be even in width. There should not be any defects. Exercise 22-5 Making a Vertical Butt Weld 1. Obtain two pieces of carbon steel measuring 1/8″ × 1 1/2″ × 6″ (3.2 mm × 40 mm × 150 mm). 2. Clean one long edge on each piece. 3. Set up the welding equipment for welding carbon steel. 4. Tack weld the two pieces together to form a butt joint with a root opening of 1/16″ (1.5 mm). 5. Weld the butt joint uphill. Use the recommended torch and welding rod angles and the keyhole method. The weld must have complete penetration. Inspection: Examine the weld for complete penetration. No porosity, underfill, or any other defects should be present in the weld. Ripples on the face and root of the weld should be even and straight. Compare your completed weld to the one shown in Figure 22-11. Welding in the Overhead Welding Position Overhead welding is the most diffi cult. It can be uncomfortable for the welder. The weld pool must be kept small when welding overhead. Use only stringer beads or very small weave beads. The torch is often held like a hammer when overhead welding. This provides fl exibility and control. The amount of current set on the welding machine to weld thin metals overhead is usually 10A less than when fl at welding. Thicker metals use 20A less current for overhead welding than for fl at welding. Pulsed welding gives very good results. It provides good penetration and gives the weld pool Goodheart-Willcox Publishing Figure 22-11. An acceptable butt weld on carbon steel that was made welding uphill. The bead is convex and straight, with evenly spaced ripples. There is no apparent undercut, underfill, or sag. Chapter 22 GTAW: Horizontal, Vertical, and Overhead Welding Positions 329 Copyright Goodheart-Willcox Co., Inc.