Tweco 190 MIG Thermal Arc Fabricator - Manual (Page 53)

FABRICATOR 190 WELDING MACHINE
Manual No. 0-4838 5-5 MANUAL GMAW WELDING
5.04 Welding Problems
FAULT CAUSE REMEDY
A. Undercut. 1. Welding arc voltage
too high. Reduce voltage by reducing the output
voltage control switch position or increase
the wire speed.
2. Incorrect torch
angle Adjust angle
3. Excessive heat
input Increase the torch travel speed and/or
reduce welding current by reducing the
output voltage control switch position or
reducing the wire speed.
4. Weld speed too fast Reduce weld speed.
B. Lack of penetration. 1. Welding current too
low
Increase welding current by increasing
wire speed and increasing voltage
selection switch position.
2. Joint preparation too
narrow or gap too
tight
Increase joint angle or gap
3. Shielding gas
incorrect
Change to a gas which gives higher
penetration
4. Weld speed too fast Reduce weld speed.
C. Lack of fusion. 1. Voltage too low Increase voltage by increasing output
voltage control switch position.
2. Weld speed too fast Reduce weld speed.
D. Excessive spatter. 1. Voltage too high Lower voltage by reducing the voltage
selection switch or increase wire speed
control.
2. Voltage too low Raise voltage by increasing the output
voltage control switch or reduce wire
speed control.
3. Weld speed too fast Reduce weld speed.
E. Irregular weld
shape.
1. Incorrect voltage and
current settings.
Convex, voltage too
low. Concave, voltage
too high.
Adjust voltage and current by adjusting
the voltage selection switch and the wire
speed control.
2. Wire is wandering Replace contact tip
3. Incorrect shielding
gas
Check shielding gas.
4. Insufficient or
excessive heat input
Adjust the wire speed control or the
output voltage control switch.
5. Weld speed too fast Reduce weld speed.
Table 5-1a: Welding Problems and Solutions