Tweco 400i Transmig - Manual (Page 46)

TRANSMIG 400 i
6-6 July 18, 2008
6.06 TIG Welding Problems
Weld quality is dependent on the selection of the correct consumables, maintenance of equipment and proper
welding technique.
1 Excessive bead build-up or poor
penetration or poor fusion at edges
of weld
Welding current is too low Increase weld current
and/or faulty joint
preparation
2 Weld bead too wide and flat or
undercut at edges of weld or
excessive burn through
Welding current is too high Decrease weld current
3 Weld bead too small or insufficient
penetration or ripples in bead are
widely spaced apart
Travel speed too fast Reduce travel speed
4 Weld bead too wide or excessive
bead build-up or excessive
penetration in butt joint
Travel speed too slow Increase travel speed
5 Uneven leg length in fillet joint Wrong placement of filler
rod Re-position filler rod
6 Electrode melts when arc is struck Electrode is connected to
the '+' terminal Connect the electrode to
the '-' terminal
7 Dirty weld pool A Electrode contaminated
through contact with work
piece or filler rod material
A Clean the electrode by
grinding off the
contaminates
B Gas contaminated with air B Check gas lines for cuts
and loose fitting or
change gas cylinder
8 Electrode melts or oxidizes when
an arc is struck
A No gas flowing to welding
region
A Check the gas lines for
kinks or breaks and gas
cylinder contents
B Torch is clogged with dust B Clean torch
C Gas hose is cut C Replace gas hose
D Gas passage contains
impurities
D Disconnect gas hose from
torch then raise gas
pressure and blow out
impurities
E Gas regulator turned off E Turn on
F Torch valve is turned off F Turn on
G The electrode is too small
for the welding current
G Increase electrode
diameter or reduce the
welding current
9 Poor weld finish Inadequate shielding gas Increase gas flow or
check gas line for gas
flow problems
Description Possible Cause Remedy