Parweld XTT-182 DV - Page 10

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10
FAULT
FINDING
Description Possible cause Remedy
Non-metallic particles
are trapped in the weld
metal (slag inclusion).
a) Non-metallic particles
may be trapped in
undercut from previous
run
(b) Joint preparation too
restricted
(c) Irregular deposits
allow slag to be trapped.
(d) Lack of penetration
with slag trapped
beneath weld bead.
(e) Rust or mill scale is
preventing full fusion.
(f) Wrong electrode for
position in which welding
is done.
a) If bad
undercut
is present,
clean slag
out and
cover with
a run from
a smaller
diameter
electrode.
(b) Allow for
adequate
penetration
and room for
cleaning out
the slag
(c) If very
bad, chip
or grind out
Irregularities
(d) Use
smaller
electrode
with sufcient
current
to give
adequate
penetration.
adequate
penetration.
Use suitable
tools to
remove all
slag from
corners
(f) Use
electrodes
designed
for position
in which
welding
is done,
otherwise
proper
control
of slag is
difcult.
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
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
Description Possible Cause Remedy
Weld bead too
wide and at
or undercut at
edges of weld
or excessive
burn through
Welding current is too
high
Decrease weld
current
Weld bead
too small or
insufcient
penetration or
ripples in bead
are widely
spaced apart
Travel speed too fast Reduce travel speed
Weld bead
too wide or
excessive
bead build up
or excessive
penetration in
butt joint
Travel speed too slow Increase travel
speed
Uneven leg
length in llet
joint
Wrong placement of
ller rod
Re-position ller rod
Electrode melts
when arc is
struck
Electrode is connected
to the ‘+’ terminal
Connect the
electrode to the ‘-‘
terminal
Dirty weld pool (a) Electrode
contaminated through
contact with work piece
or ller rod material
(b) Gas contaminated
with air
(a) Clean the elec-
trode by grinding off
the contaminates
(b) Check gas lines
for cuts and loose
tting or change gas
cylinder
Electrode melts
or oxidizes
when an arc is
struck
(a) No gas owing to
welding region
(b) Torch is clogged with
dust
(c) Gas hose is cut
(d) Gas passage
contains impurities
(e) Gas regulator is
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 and gas
cylinder contents
(b) Clean torch
(c) Replace gas
hose
(d) Disconnect gas
hose from torch
then raise gas
pressure to blow
out impurities.
(e) Turn on
(f) Turn on
(g) Increase
electrode diameter
or reduce the
welding current
Poor weld nish Inadequate shielding
gas
Increase gas ow or
check gas line for
gas ow problems
Arc utters
during TIG
welding
(a) Tungsten electrode is
too large for the welding
current
(b) Absence of oxides in
the Weld pool.
(a) Select the right
size electrode. Refer
to basic TIG welding
guide.
(b) Refer basic TIG
welding guide for
ways to reduce arc
utter