HD Manual Arc Welders
29
©2000 CIGWELD All rights reserved
Welding Problems (continued)
FAULT
CAUSE
REMEDY
4 Non-metallic
particles
are trapped in the weld
metal (slag inclusion).
A Non-metallic particles may be
trapped in undercut from previous
run.
A If bad undercut is present, clean slag
out and cover with a run from a
smaller diameter 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 corners.
E Rust or mill scale is preventing full
fusion.
E Clean joint before welding.
F Wrong electrode for position in
which welding is done.
F Use electrodes designed for position
in which welding is done, otherwise
proper control of slag is difficult.
Figure 29 - Examples of slag inclusion
Welding Problems (continued)
FAULT
CAUSE
REMEDY
5
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).
A
B
C
Welding current is too high.
Welding arc is too long.
Angle of the electrode is incorrect.
A
B
C
Reduce welding current
Reduce the length of the welding
arc.
Electrode should not be inclined less
than 45
°
to the vertical face
D Joint preparation does not allow
correct electrode angle.
D Allow more room in joint for
manipulation of the electrode.
E Electrode too large for joint.
E Use smaller gauge electrode.
F Insufficient deposit time at edge of
weave.
F Pause for a moment at edge of
weave to allow weld metal build-up.
Figure 30 - Examples of undercut
