Ryobi MMA-140 Owner's Operating Manual page 21

STICK (MMAW) WELDING TROUBLESHOOTING
Problem
Portions of the weld run
do not fuse to the
surface of the metal or
edge of the joint.
Gas pockets or voids in
weld metal (porosity).
Crack occurring in weld
metal soon after
solidification
commences.
Excessive spatter
Possible Cause
Small electrodes used on heavy
cold plate.
Welding current is too low.
Wrong electrode angle.
Travel speed of electrode is too
high.
Scale or dirt on joint surface.
High levels of sulphur in steel.
Electrodes are damp.
Welding current is too high.
Surface impurities such as oil,
grease, paint, etc.
Welding in a windy environment.
Electrode damaged ie. flux
coating incomplete.
Rigidity of joint.
Insufficient throat thickness.
Weld current is too high.
Improper welding polarity
Long Arc Length.
Weld current is too high.
Remedy
Use larger electrodes and preheat the
plate.
Increase welding current.
Adjust angle so the welding arc is
directed more into the base metal.
Reduce travel speed of electrode.
Clean surface before welding.
Use an electrode that is designed for
high sulphur steels.
Dry electrodes before use.
Reduce welding current.
Clean joint before welding.
Shield the weld area from the wind.
Discard damaged electrodes and only
use electrodes with a complete flux
coating.
Redesign to relieve weld joint of
severe stresses or use crack
resistance electrodes.
Travel slightly slower to allow greater
build up in throat.
Decrease welding current.
Make sure the electrode holder is
plugged into the positive "+" output
terminal.
Move the electrode closer into the
weld joint.
Decrease welding current.
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