17
16
Problem
Likely Reason
Outcome
GMAW/MIG Models
The machine feeds slowly
and then speeds up after
3-5 seconds.
Creep mode is selected, or
machine has a permanent
creep mode function.
Some models have a creep
mode function that cannot be
adjusted. Other models have
a push button selection for
creep mode on/off.
Nothing happens for first
x seconds after trigger is
pulled.
Pre gas is selected to x
seconds.
Allow for Pre Gas time, or
adjust time.
The arc starts normally but
then stops x seconds.
Spot time is selected to x
seconds.
Spot time selection should be
adjusted to 0 seconds.
The arc does not stop
after trigger is released.
Latch mode is selected.
Latch mode should be
switched off.
Motor continues to run
once arc is extinguished.
Latch mode is selected.
Latch mode should be
switched off.
Weld is contaminated with
small bubbles (presence
of porosity).
Air in the gas hose. The
torch gas hose has not been
purged sufficiently.
The gas hose is not securely
connected at the machine or
at the regulator.
Air is being drawn into arc
through torch nozzle
Purge the system and
confirm sufficient gas flow
through the regulator.
Ensure the gas connections
from regulator through to the
torch connection are suf-
ficiently tightened.
Remove nozzle, check O ring
on torch head, check
condition of insulator in
nozzle
Wire feed stutters and arc
is erratic. Also, motor turns
correctly under no load.
Torch consumables are
blocked/partially blocked.
Rusty MIG wire.
Liners and contact tips are
consumable and wear over
time.
Replace the torch liner and
reduce wire feed tension.
Presence of porosity at
weld start.
The torch gas hose has not
been purged sufficiently.
Purge the system and
confirm sufficient gas flow
through the regulator.
