Stick (Mmaw) Welding Troubleshooting - Ryobi MMA-140 Owner's Operating Manual

STICK (MMAW) WELDING TROUBLESHOOTING

Problem
Welding current
varying.
A gap is left by failure of
the weld metal to fill the
root of the weld.
Non-metallic particles
are trapped in the weld
metal.
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).
Possible Cause
Control knob is set at a value that
causes the welding current to vary
excessively with the arc length.
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.
Irregular deposits allow slag to be
trapped.
Lack of penetration with slag
trapped beneath weld bead.
Rust or mill scale is 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.
Remedy
Reduce the control knob until welding
current is reasonably constant while
prohibiting the electrode from sticking
to the workpiece when you "dig" the
electrode into the workpiece.
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.
Allow 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 give adequate penetration.
Use suitable tools to remove all slag
from corners.
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 be inclined less
than 45° to the vertical face.
Allow more room in joint for
manipulation of the electrode.
Use smaller gauge electrode.
Pause for a moment at edge of weave
to allow weld metal buildup.
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