Tweco 200 ACDC Arcmaster(Feb2006) - Manual (Page 48)

42
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
Welding current is too low.
Electrode too large for joint.
Insufficient gap. A
B
C
Increase welding current.
Use smaller diameter
electrode.
Allow wider gap.
D Incorrect sequence. D Use correct build-up sequence.
Figure 8. Example of Insufficient Gap or Incorrect Sequence