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Gas Tungsten Arc Welding Handbook
Overlap. Weld metal that has fl owed over the edge of the joint and improperly fused with the base metal.
How to correct:
• Clean edge of weld joint.
• Remove oxides from previous welds.
• Reduce size of bead.
• Increase travel speed.
Undercut. Lack of fi ller metal at the toe of the weld metal.
How to correct:
• Decrease travel speed.
• Increase dwell time at edge of joint on
weave beads.
• Decrease arc length.
• Decrease amperage.
• Decrease torch angle.
Concave weld. A concave weld occurs when insuffi cient metal is added to fi ll the joint above the groove edges.
How to correct:
• Add additional fi ller metal on the fi ll
passes.
• Use stringer beads on crown pass.
Convex crown. A weld that is peaked in the center.
How to correct:
• Use less fi ller metal on the crown bead.