Stick Welding Problems - Boss ARC 140 Operating Manual

11. Arc start is not smooth.
9.03

Stick welding problems

Description
1 Gas pockets
voids in weld metal
(Porosity).
2 Crack occurring in
weld metal soon
after solidification
commences.
3 A gap is left by
failure of the weld
metal to fill the root
of the weld.
4 Portions of the weld
run do not fuse to
the surface of the
metal or edge of the
joint.
5 Non-metallic
particles are trapped
in the weld metal
(slag inclusion).
BOSS ARC 140¡¢ 160 Operating Manual
A Tungsten electrode is too large for
the welding current.
B The wrong electrode is being used
for the welding job.
C Gas flow rate is too high.
D Incorrect shielding gas is being
used.
E Poor work clamp connection to
work piece.
Cause
A Electrodes are damp.
or
B Welding current is too large.
C Surface impurities
grease, paint, etc.
A Rigidity of joint.
B Insufficient throat thickness.
C Cooling rate is too high.
A Welding current is too low.
B Electrode too large for joint.
C Insufficient gap.
D Incorrect sequence.
A Small electrodes used on heavy cold
plate.
B Welding current is too low.
C Wrong electrode angle.
D Travel speed of electrode is too high.
E Scale or dirt on joint surface.
A Non-metallic particles may be trapped
in undercut from previous run.
B Joint preparation too restricted.
C Irregular deposits allow slag to be
trapped.
D Lack of penetration with slag trapped
beneath weld bead.
E Rust or mill scale is preventing full
fusion.
F Wrong electrode for position in which
welding is done.
A Select the right size electrode.
B Select the right electrode type.
C Select the correct rate for the
D Select the right shielding gas.
E Improve connection to work piece.
Table 15
A Dry electrodes before use.
B Reduce welding current.
such as: oil, C Clean joint before welding.
A Redesign to relieve weld joint of
B Travel slightly slower to allow greater
C Preheat plate and cool slowly.
A Increase welding current.
B Use smaller diameter electrode.
C Allow wider gap.
D Use correct build-up sequence.
A Use larger electrodes and preheat
B Increase welding current.
C Adjust angle so the welding is
D Reduce travel speed of electrode.
E Clean surface before welding.
A If bad undercut is present, clean slag
B Allow for adequate penetration and
C If very bad, chip or grind out
D Use smaller electrode with sufficient
E Clean joint before welding.
F Use electrodes designed for position
Table 16
- 21 -
Refer to basic TIG welding guide.
Refer to basic TIG welding guide
welding job.
Refer to Basic TIG Welding Guide.
Remedy
severe stresses or
resistance electrodes.
build up in throat.
the plate.
directed more into the base metal.
out and cover with a run from a
smaller diameter electrode.
room for cleaning out the slag.
irregularities.
current to give adequate penetration.
Use suitable tools to remove all slag
from corners.
in which welding is done, otherwise
proper control of slag is difficult.
use crack