Tweco ArcMaster 401S - Manual (Page 49)

ARCMASTER 401S POWER SOURCE
Manual 0-5345 4-11 BASIC WELDING GUIDE
FAULT CAUSE REMEDY
4 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 Welding current is too
high.
A Reduce welding current.
B Welding arc is too long. B Reduce the length of the welding arc.
C Angle of the electrode is
incorrect.
C 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 buildup.
5 Portions of the
weld run do not
fuse to the surface
of the metal or
edge of the joint.
A Small electrodes used on
heavy cold plate.
A Use larger electrodes and preheat the plate.
B Welding current is too low. B Increase welding current.
C Wrong electrode angle.
C Adjust angle so the welding arc is directed more
into the base metal.
D Travel speed of electrode
is too high.
D Reduce travel speed of electrode.
E Scale or dirt on joint
surface.
E Clean surface before welding.
Art: A-04972
Figure 2: Example of Lack of Fusion
6 Gas pockets or
voids in weld
metal (porosity)
A High levels of sulphur in
steel.
A Use an electrode that is designed for high sul-
phur steels.
B Electrodes are damp. B Dry electrodes before use.
C Welding current is too
high.
C Reduce welding current.
D Surface impurities such as
oil, grease, paint, etc.
D Clean joint before welding.
E Welding in a windy envi-
ronment.
E Shield the weld area from the wind.
F Electrode damaged ie flux
coating incomplete.
F Discard damaged electrodes and only use elec-
trodes with a complete flux coating.