Thermal Arc ARCMASTER 200 TS Service Manual page 37

8
200TS BASIC TROUBLESHOOTING
Description
4 Portions of the weld run
do not fuse to the
surface of the metal or
edge of the joint.
Description
5 Non-metallic particles
are trapped in the weld
metal (slag inclusion).
Possible Cause
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.
Lack of fusion caused by dirt,
electrode angle incorrect, rate
of travel too high
Lack of side fusion, scale
dirt, small electrode,
amperage too low
Figure 8-2: Example of lack of fusion
Possible Cause
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.
Table 8-2: STICK Welding Problems
Not cleaned, or
incorrect electrode
Figure 8-3: Examples of slag inclusion
A Use larger electrodes and pre-heat the
plate.
B Increase welding current.
C Adjust angle so the welding arc is
directed more into the base metal.
D Reduce travel speed of electrode.
E Clean surface before welding.
Lack of inter-run Fusion
Lack of Root Fusion
A If bad undercut is present, clean slag out
and cover with a run from a smaller
diameter electrode.
B Allow for adequate penetration and room
for cleaning out the slag.
C If very bad, chip or grind out irregularities.
D Use smaller electrode with sufficient
current to give adequate penetration. Use
suitable tools to remove all slag from
corners.
E Clean joint before welding.
F Use electrodes designed for position in
which welding is done, otherwise proper
control of slag is difficult.
Slag trapped in
undercut
Slag trapped in root
8 – 3
Remedy
Remedy