Copyright Goodheart-Willcox Co., Inc. Chapter 8 Manual Welding Techniques 145 Problem Areas and Corrections: 1. Convex weld crown. Possible cause: Too much filler metal or travel speed too slow. Solution: Add less filler metal. Solution: Increase the travel speed. 2. Concave weld crown. Possible cause: Not enough filler metal or travel speed too high. Solution: Add more filler metal. Solution: Decrease the travel speed. 3. Leg sizes are not equal. Possible cause: Incorrect torch angles. Solution: Reposition the torch to keep the weld pool even. Possible cause: Variation in the size of the weld pool. Solution: Maintain a consistent travel speed and feed the welding rod as needed to keep the weld pool size consistent. 4. Undercut. Possible cause: Improper torch work angle. Solution: Maintain the proper torch angles. Possible cause: Uneven weld pool. Solution: Add welding rod to the center of the pool. Reading the Weld Pool The ability to read a weld pool is a very important skill for welders, particularly in GTAW because the weld pool is relatively small. This skill develops with practice and an increased understanding of the vari- ables that affect the weld. By reading the weld pool, a welder can tell when the travel speed is too fast or too slow and when torch angles are incorrect. The weld pool reveals discontinuities as they happen. Reading the weld pool enables the welder to make “on-the-fl y” adjustments to ensure a quality weld. Groove Weld Discontinuities and Corrective Actions C ommon groove weld discontinuities may be noticed during the welding operation or later during the inspec- tion of the completed weld. These discontinuities are listed and shown with suggestions for corrective actions. Square groove V-groove Lack of (incomplete) penetration. A weld that does not properly penetrate into the weld joint. How to correct: • Open groove angle. • Decrease root face. • Increase root opening. • Increase amperage. • Decrease arc length. • Decrease travel speed. • Decrease torch angle. Lack of fusion. Fusion did not occur between the weld metal and fusion faces or adjoining weld beads. How to correct: • Clean weld joint before welding. • Remove oxides from previous welds. • Open groove angle. • Decrease root face. • Increase root opening. • Increase amperage. • Decrease arc length. • Decrease travel speed. • Decrease torch angle. Square groove V-groove