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MULTIMIG 200 PFC MV
OWNER’S MANUAL
The electrode needs to be moved along fast enough to prevent
the slag pool from getting ahead of the arc. To complete the joint
in thin plate, turn the job over, clean the slag out of the back and
deposit a similar weld.
Heavy plate will require several runs to complete the joint. After
completing the first run, chip the slag out and clean the weld
with a wire brush. It is important to do this to prevent slag being
trapped by the second run. Subsequent runs are then deposited
using either a weave technique or single beads laid down in the
sequence shown in Figure 1-22. The width of weave should not
be more than three times the core wire diameter of the electrode.
When the joint is completely filled, the back is either machined,
ground or gouged out to remove slag which may be trapped
in the root, and to prepare a suitable joint for depositing the
backing run. If a backing bar is used, it is not usually necessary to
remove this, since it serves a similar purpose to the backing run in
securing proper fusion at the root of the weld.
B. Fillet Welds
These are welds of approximately triangular crosssection made
by depositing metal in the corner of two faces meeting at right
angles. Refer to Figure 1-14, 1-23 and 1-24.
A piece of angle iron is a suitable specimen with which to begin,
or two lengths of strip steel may be tacked together at right
angles. Using a 3.2mm 6012 Stick electrode at 100 amps, position
angle iron with one leg horizontal and the other vertical. This is
known as a horizontal-vertical (HV) fillet.
Strike the arc and immediately bring the electrode to a position
perpendicular to the line of the fillet and about 45º from the
vertical. Some electrodes require being sloped about 20º away
from the perpendicular position to prevent slag from running
ahead of the weld. Refer to Figure 1-23.
Do not attempt to build up much larger than 6.4mm width with a
3.2mm electrode, otherwise the weld metal tends to sag towards
the base, and undercut forms on the vertical leg. Multi-runs can
be made as shown in Figure 1-24. Weaving in HV fillet welds is
undesirable.
C. Vertical Welds
1. Vertical Up
Tack weld a three feet length of angle iron to your work bench in
an upright position. Use a 3.2mm E7014 Stick electrode and set
the current at 100 amps. Make yourself comfortable on a seat in
front of the job and strike the arc in the corner of the fillet. The
electrode needs to be about 10º from the horizontal to enable a
good bead to be deposited. Refer Fig. 1-25.
Use a short arc, and do not attempt to weave on the first run.
When the first run has been completed deslag the weld deposit
and begin the second run at the bottom. This time a slight
weaving motion is necessary to cover the first run and obtain
good fusion at the edges.
