Tweco 175 SE Arc Master - Manuel (Page 39)

SERVICE ARC MASTER 175 SE
Manual 0-5054 5-3 SERVICE
5.03 TIG Welding Problems
Weld quality is dependent on the selection of the correct consumables, maintenance of equipment and proper welding
technique.
Description Possible Cause Remedy
1. Excessive beard build-up or
poor penetration or poor fusion
at edges of weld.
Welding current is too low Increase weld current and/or
change 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 welding current.
3. Weld bead too small or insuf-
ficient 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 is 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
“+” Positive Output Terminal.
Connect the electrode to the
“-“ Negative Output Terminal.
7. Dirty weld pool. A. Electrode contaminated
through contact with work
piece or filler rod material.
B. Gas contaminated with air.
A. Cle a n t he e le c trode b y
grinding contaminates off.
B. Check gas lines for cuts and
loose fitting or change gas
cylinder.
8. Poor weld finish. Inadequate shielding gas. Increase gas flow or check gas
line for problems
9. Arc flutters during TIG
welding.
Tungsten electrode is too large
for the welding current.
Select the right size electrode.
Refer to section Tungsten Elec-
trode Current Ranges.
10. Welding arc cannot be esta-
blished.
A. Work clamp is not connected
to the work piece or the work/
torch leads are not connected to
the correct welding terminals.
B. Torch lead is disconnected.
C. Gas flow incorrectly set, cyl-
inder empty or the torch valve
is off.
A. Connect the work clamp to
the work piece or connect
the work/torch leads to the
correct welding terminals.
B. Connect it to the “-“ Negative
Output Terminal.
C. Select the right flow rate,
change cylinder or turn torch
valve on.
11. Electrode melts or oxidizes
when an arc is struck.
A. No gas is flowing to welding
region.
B. Torch is clogged with dust.
C. Gas hose is cut.
D. Gas passage contains impuri-
ties.
E. Gas regulator turned off.
F. Torch valve is turned off.
G. The electrode is too small for
the welding current.
A. Check the gas lines for kinks
or breaks or cylinder contains
gas.
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.