Stick (Smaw) Welding Troubleshooting - Firepower MST 180i Operating Manual

Firepower MST 180i

4.05 Stick (SMAW) 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.
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).
BASIC WELDING GUIDE
CAUSE
ARC FORCE control knob is
set at a value that causes the
welding current to vary ex-
cessively 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 re-
stricted.
C Irregular deposits allow slag
to be trapped.
D Lack of penetration with slag
trapped beneath weld bead.
E Rust or mill scale is prevent-
ing full fusion.
F Wrong electrode for position
in which welding is done.
Insufficient Gap
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.
Reduce the ARC FORCE control knob until welding
current is reasonably constant while prohibiting 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 clean-
ing 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.
Art # A-05866_AC
Incorrect Sequence
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 (SMAW) mode.
4-16
REMEDY
Manual 0-5339