Mma (Stick) Troubleshooting - Weldclass WeldForce WF-140ST Operating Instructions Manual

11.9 MMA (Stick) Troubleshooting

Fault
A gap is left by failure of the
weld metal to fill the root of
the weld.
Figure 33
Non-metallic particles are
trapped in the weld metal.
Figure 34
A groove has been formed in
the base metal adjacent to
the top of a weld and has not
been filled by the weld metal
(undercut).
Figure 35
34
Cause
Welding current too low.
Electrode too large for joint.
Insufficient gap.
Non-metallic particles may be
trapped in undercut from
previous run.
Joint preparation too restricted. Allow
Irregular deposits allow slag to
be trapped.
Lack of penetrations with slag
trapped beneath weld bead.
Rust or mill scale or preventing
full fusion.
Wrong electrode for position in
which welding is done.
Welding current is too high.
Welding arc is too long.
Angle of the electrode is
incorrect.
Joint preparation does not
allow correct electrode angle.
Electrode too large for joint.
Insufficient deposit time at
edge of weave.
© Weldclass | E.&O.E. | Edition 1.1 | 2019.05.03
Remedy
Increase welding current.
Use smaller diameter
electrode.
Allow wider gap.
If a bad undercut is present
clean slag bout and cover with
a run from a smaller gauge
electrode.
for adequate
penetration and room for
cleaning out the slag.
If very bad, chip or grind out
irregularities.
Use smaller electrode with
sufficient current to
adequate penetrations. Use
suitable tools to remove all slag
from comers.
Clean joint before welding.
Use electrodes designed for
position in which welding is
done, otherwise proper control
of slag is difficult.
Reduce welding current.
Reduce the length of the
welding arc.
Electrode should not
inclined less than 45° to the
vertical face.
Allow more room for joint for
manipulation of the electrode.
Use smaller gauge electrode.
Pause for a moment at edge of
weave to allow weld metal
build-up.
.
give
be