Stick (Mma) Welding Troubleshooting - Thermal Arc FABRICATOR 181i Operating Manual

4.05 Stick (MMA) Welding Troubleshooting

FAULT
1 Welding current
varying
2 A gap is left by
failure of the weld
metal to fill the
root of the weld.
3 Non-metallic par-
ticles are trapped
in the weld metal.
Art # A-05866_AC
Incorrect Sequence
Insufficient Gap
4 A groove has been
formed in the base
metal adjacent to
the toe of a weld
and has not been
filled by the weld
metal (undercut).
Manual 0-5151
CAUSE
ARC FORCE control knob
is set at a value that
causes the welding current
to vary excessively with
the arc length.
A Welding current too low
B Electrode too large for
joint.
C Insufficient gap.
A Non-metallic particles may
be trapped in undercut
from previous run.
B Joint preparation too
restricted.
C Irregular deposits allow
slag to be trapped.
D Lack of penetration with
slag trapped beneath weld
bead.
E Rust or mill scale is pre-
venting full fusion.
F Wrong electrode for posi-
tion in which welding is
done.
Figure 1-Example of insufficient gap or incorrect sequence
A Welding current is too
high.
B Welding arc is too long.
C Angle of the electrode is
incorrect.
D Joint preparation does not
allow correct electrode
angle.
E Electrode too large for
joint.
F Insufficient deposit time at
edge of weave.
G Power source is set for
MIG (GMAW) welding.
REMEDY
Reduce the ARC FORCE control knob until weld-
ing current is reasonably constant while prohibit-
ing the electrode from sticking to the work piece
when you "dig" the electrode into the workpiece.
A Increase welding current.
B Use smaller diameter electrode.
C Allow wider gap.
A If a bad undercut is present clean slag bout and
cover with a run from a smaller gauge electrode.
B Allow for adequate penetration and room for
cleaning out the slag.
C If very bad, chip or grind out irregularities.
D Use smaller electrode with sufficient current to
give adequate penetration. Use suitable tools to
remove all slag from comers.
E Clean joint before welding.
F Use electrodes designed for position in which
welding is done, otherwise proper control of slag
is difficult.
A Reduce welding current.
B Reduce the length of the welding arc.
C Electrode should not be inclined less than 45° to
the vertical face.
D Allow more room in joint for manipulation of the
electrode.
E Use smaller gauge electrode.
F Pause for a moment at edge of weave to allow
weld metal buildup.
G Set power source to STICK (MMA) mode.
4-21
Fabricator 181i
BASIC WELDING GUIDE