Chapter 8 Manual Welding Techniques
141
Problem Areas and Corrections:
1. Undercut.
Possible cause: Insuffi cient amount of fi ller 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 fi ller metal added to
weld pool.
Solution: Add fi ller 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 fi ller metal addition.
Solution: Add fi ller 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 fi ller 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 fi lm (both
passes).
5. Realign the torch and weld the second pass.
A. Add suffi cient fi ller 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: Insuffi cient fi ller 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 fi ller metal addition.
Solution: Add fi ller metal to create a consistently
sized crown.
3. Uneven penetration.
Possible cause: Inconsistent travel speed.
Solution: Maintain a consistent travel speed.
Possible cause: Inconsistent fi ller metal addition.
Solution: Add fi ller 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)