Tig Welding Problems - Thermal Arc ARCMASTER 300 MST Operating Manual

9.03 TIG Welding Problems

Weld quality is dependent on the selection of the correct consumables, maintenance of equipment and
proper welding technique.
Description
1 Excessive beard build-
up or poor penetration
or poor fusion at edges
of weld.
2 Weld bead too wide
and flat or undercut at
edges of weld
or excessive
burn through.
3 Weld bead too small or
insufficient penetration
or ripples in bead are
widely spaced apart.
4 Weld bead too wide or
excessive bead build up
or excessive penetra-
tion in
butt joint.
5 Uneven leg length in
fillet joint.
6 Electrode melts when
arc is struck.
7 Dirty weld pool.
8 Electrode melts or
oxidizes when an arc is
struck.
Possible Cause
Welding current is too low.
Welding current is too high.
Travel speed too fast.
Travel speed too slow.
Wrong placement of filler rod.
Electrode is connected to the
'+' terminal.
A Electrode contaminated through
contact with work piece or filler
rod material.
B Gas contaminated with air.
A No gas flowing to
welding region.
B Torch is clogged with dust.
C Gas hose is cut.
D Gas passage contains impurities.
E Gas regulator turned OFF.
F Torch valve is turned OFF.
G The electrode is too small for
the welding current.
41
Remedy
Increase weld current and/or faulty
joint preparation.
Decrease weld current.
Reduce travel speed.
Increase travel speed.
Re-position filler rod.
Connect the electrode to the
'−' terminal.
A Clean the electrode by grinding off
the contaminates.
B Check gas lines for cuts
and loose fitting or change
gas cylinder.
A Check the gas lines for kinks
or breaks and gas
cylinder contents.
B Clean torch
C Replace gas hose.
D Disconnect gas hose from torch
then raise gas pressure and blow
out impurities.
E Turn ON.
F Turn ON.
G Increase electrode diameter or
reduce the welding current.