Tweco 186 DC Inverter - Manual (Page 64)

186 AC/DC INVERTER BASIC WELDING
BASIC WELDING GUIDE 4-10 Manual 0-5237
4.02 STICK (SMAW) Welding Troubleshooting
FAULT CAUSE REMEDY
1 Welding current
varying
ARC FORCE control knob
is set at a value that
causes the welding current
to vary excessively with
the arc length.
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.
2 A gap is left by
failure of the weld
metal to fill the
root of the weld.
A Welding current too low A Increase welding current.
B Electrode too large for
joint.
B Use smaller diameter electrode.
C Insufficient gap. C Allow wider gap.
3 Non-metallic par-
ticles are trapped
in the weld metal.
A Non-metallic particles may
be trapped in undercut
from previous run.
A If a bad undercut is present clean slag bout and
cover with a run from a smaller gauge electrode.
B Joint preparation too
restricted.
B Allow for adequate penetration and room for
cleaning out the slag.
C Irregular deposits allow
slag to be trapped.
C If very bad, chip or grind out irregularities.
D Lack of penetration with
slag trapped beneath weld
bead.
D Use smaller electrode with sufficient current to
give adequate penetration. Use suitable tools to
remove all slag from comers.
E Rust or mill scale is pre-
venting full fusion.
E Clean joint before welding.
F Wrong electrode for posi-
tion in which welding is
done.
F Use electrodes designed for position in which
welding is done, otherwise proper control of slag
is difficult.
Art: A-04971
Figure 1 - Example of insufficient gap or incorrect sequence