16
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 sec-
ond 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 cross-
section 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
E7014 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.
Electrode Position
for HV Fillet Weld
(Fig 1-23)
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.
Multi-Runs in HV Fillet Weld
(Fig 1-24)
Single Run Vertical Fillet Weld
(Fig 1-25)
Weaving motion for
second and subsequent
runs
Pause at edge
of weave
Multi Run Vertical Fillet Weld
(Fig 1-26)
Use a short arc, and do not attempt to weave on the
first run. When the first run has been completed de-
slag the weld deposit and begin the second run at
the bottom. This time a slight weaving motion is nec-
essary to cover the first run and obtain good fusion
at the edges.
At the completion of each side motion, pause for a
moment to allow weld metal to build up at the edg-
es, otherwise undercut will form and too much metal
will accumulate in the centre of the weld. Figure
1-26 illustrates multi-run technique and Figure 1-27
shows the effects of pausing at the edge of weave
and of weaving too rapidly.
Summary of Contents for EZITIG 200AC/DC
Page 1: ...OPERATING INSTRUCTIONS EZITIG 200AC DC 200A MULTI PROCESS TIG WELDER www weldtech net nz...
Page 11: ...11 EZITIG200 AC DC Welding Machine www weldtech net nz Wiring Diagram...
Page 18: ...18 MMA Stick Troubleshooting...
Page 21: ...21 EZITIG200 AC DC Welding Machine www weldtech net nz TIG Welding Troubleshooting...
