ESAB Firepower MST-200 User Manual

8 TROUBLESHOOTING
0463 766 001 - 72 - © ESAB AB 2021
Basic MIG (GMAW/FCAW) welding troubleshooting
Table 25: MIG (GMAW /FCAW) welding problems
Type of fault
Cause
Corrective action
Undercut
Welding arc voltage is too
high.
Decrease voltage or
increase the wire feed
speed.
Incorrect MIG gun angle.
Adjust angle.
Excessive heat input.
Increase the MIG gun travel
speed and/or decrease
welding current by
decreasing the voltage or
decreasing the wire feed
speed.
Lack of penetration
Welding current is too low
Increase welding current by
increasing wire feed speed
and increasing voltage.
Joint preparation is too
narrow or gap is too tight.
Increase joint angle or gap.
Shielding gas is incorrect.
Change to a gas which
gives higher penetration.
Lack of fusion
Voltage is too low.
Increase voltage.
Excessive spatter
Voltage is too high.
Decrease voltage or
increase the wire speed
control.
Voltage is too low.
Increase the voltage or
decrease wire speed.
Irregular weld shape
Incorrect voltage and
current settings. Convex,
voltage is too low. Concave,
voltage is too high.
Adjust voltage and current
by adjusting the voltage
control and the wire speed
control.
Wire is wandering.
Replace velocity contact tip.
Incorrect shielding gas.
Check shielding gas.
Insufficient or excessive
heat input.
Adjust the wire speed
control or the voltage
control.
Weld cracking
Weld beads are too small.
Decrease travel speed.
Weld penetration is narrow
and deep.
Reduce current and voltage
and increase MIG gun travel
speed or select a lower
penetration shielding gas.
Excessive weld stresses.
Increase weld metal
strength or revise design.
Excessive voltage.
Decrease voltage.
Cooling rate is too fast.
Slow the cooling rate by
preheating part to be
welded or cool slowly.

ESAB Firepower MST-200 Specifications

General

Brand	ESAB
Model	Firepower MST-200
Category	Welding System
Language	English