Copyright Goodheart-Willcox Co., Inc. Chapter 8 Manual Welding Techniques 141 Problem Areas and Corrections: 1. Undercut. Possible cause: Insufficient amount of filler metal added. Solution: Add rod in the top and center of the weld pool. Possible cause: Improper torch angles. Solution: Maintain proper torch angles. 2. High crown. Possible cause: Too much filler metal added to weld pool. Solution: Add filler metal in smaller amounts. Solution: Use smaller diameter welding rod. 3. Uneven penetration or lack of penetration. Possible cause: Inconsistent travel speed. Solution: Maintain a consistent travel speed. Possible cause: Inconsistent filler metal addition. Solution: Add filler metal to maintain a consistent crown on the weld pool. Possible cause: Incorrect torch angles. Solution: Maintain the proper torch angles. Possible cause: Heat buildup in the weld pool. Solution: Increase travel speed as the plates get hotter. Welding Procedure Number 8-6 Weld joint type: Square-groove butt Position: Flat Material type: Cold-rolled steel Thickness: 11 gauge Filler metal: ER70S-2 or 6 Diameter: 3/32″ (2.4 mm) or 1/8″ (3.2 mm) (welder’s preference) Machine setup: DCEN high-frequency start Shielding gas: Argon CFH: 15–25 Tungsten type: 1%, 1.5%, or 2% lanthanated, ceriated, or thoriated Diameter: 3/32″ (2.4 mm) (tapered) Procedure: 1. Prepare and clean the materials. 2. Tack weld the plates with 3/32″ (2.4 mm) or 1/8″ (3.2 mm) spacing, depending on the filler being used. Mount the joint approximately 1/8″ (3.2 mm) above the table with metal blocks. 3. Weld the root pass to ensure full penetration. A. Maintain the torch on the weld pool with the proper angles. Use the same work and travel angles shown in Figure 8-14. 4. Wire brush the weld to remove the oxide film (both passes). 5. Realign the torch and weld the second pass. A. Add sufficient filler metal to create a slightly convex weld bead and widen the weld pool just beyond the edges of the joint. Problem Areas and Corrections: 1. Undercut. Possible cause: Insufficient filler metal added to the weld pool. Solution: Add welding rod to the edge of the weld pool on the crown pass. Solution: Hold the torch at the edge of the weld pool when adding welding rod. 2. Uneven crown. Possible cause: Inconsistent travel speed. Solution: Maintain a consistent travel speed. Possible cause: Inconsistent filler metal addition. Solution: Add filler metal to create a consistently sized crown. 3. Uneven penetration. Possible cause: Inconsistent travel speed. Solution: Maintain a consistent travel speed. Possible cause: Inconsistent filler metal addition. Solution: Add filler metal to create a consistently sized crown. Possible cause: Electrode not centered on pool. Solution: Make sure torch is centered over the centerline of the joint. Possible cause: Inconsistent torch height. Solution: Keep the tip of the electrode a consistent distance from the weld pool during each pass. Welding Procedure Number 8-7 Weld joint type: Square-groove butt Position: Horizontal Material type: Cold-rolled steel Thickness: 11 gauge Filler metal: ER70S-2 or 6 Diameter: 3/32″ (2.4 mm) or 1/8″ (3.2 mm) (welder’s preference) Machine setup: DCEN Shielding gas: Argon CFH: 10–15 Tungsten type: 2% thoriated Diameter: 3/32″ (2.4 mm) (tapered)