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.
