Tweco 180 Portable MIG - Manual (Page 53)

MAINTENANCE FABRICATOR 140, 180
July 20, 2007 5-3 Manual 0-4991
5.05 Welding Problems
FAULT CAUSE REMEDY
1 Undercut. A Welding arc voltage
too high.
A Reduce voltage by reducing the voltage
selection switch position or increase the
wire feed speed.
B Incorrect torch
angle
B Adjust angle
C Excessive heat input C Increase the torch travel speed and/or
reduce welding current by reducing the
voltage selection switch position or
reducing the wire feed speed.
2 Lack of penetration. A Welding current too
low
A Increase welding current by increasing
wire feed speed and increasing voltage
selection switch position.
B Joint preparation
too narrow or gap
i h
B Increase joint angle or gap
C Shielding gas
incorrect
C Change to a gas which gives higher
penetration
3 Lack of fusion. Voltage too low Increase voltage by increasing voltage
selection switch position.
4 Excessive spatter. A Voltage too high A Lower voltage by reducing the voltage
selection switch or increase wirespeed
control.
B Voltage too low B Raise voltage by increasing the voltage
selection switch or reduce wirespeed
control.
5 Irregular weld shape. A Incorrect voltage
and current settings.
Convex = voltage too
low. Concave =
voltage too high.
A Adjust voltage and current by adjusting
the voltage selection switch and the
wirespeed control.
B Wire is wandering B Replace contact tip
C Incorrect shielding
gas
C Check shielding gas
D Insufficient or
excessive heat input
D Adjust the wirespeed control or the
voltage selection switch
Table 5-1a: Welding Problems