Chapter 8 Manual Welding Techniques
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Problem Areas and Corrections:
1. Convex weld crown.
Possible cause: Too much fi ller metal or travel
speed too slow.
Solution: Add less fi ller metal.
Solution: Increase the travel speed.
2. Concave weld crown.
Possible cause: Not enough fi ller metal or travel
speed too high.
Solution: Add more fi ller 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 Defects and Corrective Actions
C ommon groove weld defects may be noticed during the welding operation or later during the inspection of the
completed weld. These defects are listed and illustrated 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