Tweco 300 TS Arcmaster(April2006) - Manual (Page 49)

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Description Possible Cause Remedy
12 Arc start is not
smooth.
A Tungsten electrode is too large
for the welding current.
A Select the right size
electrode. Refer to Basic
TIG Welding Guide.
B The wrong electrode is being
used for the welding job.
B Select the right electrode
type. Refer to Basic TIG
Welding Guide.
C Gas flow rate is too high. C Select the correct rate for the
welding job. Refer to Basic TIG
Welding Guide.
D Incorrect shielding gas is
being used.
D Select the right shielding gas.
Refer to Basic TIG
Welding Guide.
E Poor work clamp connection
to work piece.
E Improve connection to
work piece.
10.02 Stick Welding Problems
Description Possible Cause Remedy
1 Gas pockets or
voids in weld metal
(Porosity).
A
B
C
Electrodes are damp.
Welding current is too high.
Surface impurities such as oil,
grease, paint, etc.
A
B
C
Dry electrodes before use.
Reduce welding current.
Clean joint before welding.
2 Crack occurring in
weld metal soon
after solidification
commences.
A
B
C
Rigidity of joint.
Insufficient throat thickness.
Cooling rate is too high. A
B
C
Redesign to relieve weld joint of
severe stresses or use crack
resistance electrodes.
Travel slightly slower to allow
greater build up in throat.
Preheat plate and cool slowly.
3 A gap is left by
failure of the weld
metal to fill the
root of the weld.
A
B
C
D
Welding current is too low.
Electrode too large for joint.
Insufficient gap.
Incorrect sequence. A
B
C
D
Increase welding current.
Use smaller diameter electrode.
Allow wider gap.
Use correct build-up sequence.
Figure 8. Example of Insufficient Gap or Incorrect Sequence