7
WIRE TYPE AND SIZE
The correct choice of wire type involves a
variety of factors, such as welding
position, work piece material type,
thickness, and condition of surface to be
welded. The American Welding Society,
AWS, has set up certain requirements for
each type of wire.
The AWS classification for self-shielding
wire (FCAW process) is a multi digit
number preceded by the letter E.
WELD ANGLE
Weld angle is the angle at which the
diffuser nozzle is held during the
welding process. Using the correct angle
ensures proper penetration and bead
formation. As different welding
positions and weld joints become
necessary, nozzle angle becomes an
increasingly important factor in
obtaining a satisfactory weld. Weld
angle involves two positions - travel
angle and work angle.
Travel angle is the angle in the line of
welding and may vary from 5º to 45º
from the vertical, depending on welding
conditions.
Work angle is the angle from horizontal,
measured at right angles to the line of
welding. For most applications, a 45º
travel angle and 45º work angle is
sufficient. For specific applications,
consult an arc welding handbook.
WIRE SPEED - WF2000
The wire speed is controlled by the knob
on the front panel. The speed needs to
be “tuned” to the rate at which the wire
is being melted in the arc. Tuning is one
of the most critical functions in wire feed
welding. Tuning should be performed
on a scrap piece of metal the same type
and thickness as that to be welded.
Begin welding with one hand
“dragging” the gun nozzle across the
scrap piece while adjusting the wire
speed with the other hand. Too slow of
speed will cause sputtering and the wire
will burn up into the contact tip (See
Figure 17). Too fast a speed will also
cause a sputtering sound and the wire
will push into the plate before melting.
A smooth buzzing sound indicates the
wire speed is properly tuned. Repeat the
tuning procedure each time there is a
change in heat setting, wire diameter or
type, or work piece material type or
thickness.
TRAVEL SPEED
The travel speed is the rate at which the
wire is moved across the weld area.
Factors such as diameter and type of
weld wire, amperage, position, and
work piece material thickness all effect
the speed of travel necessary for
completing a good weld (See Fig. 17).
When the speed is too fast, the bead is
narrow and bead ripples are pointed as
shown. When the speed is too slow, the
weld metal piles up and the bead is high
and wide.
SLAG REMOVAL
Wear ANSI
approved safety
glasses (ANSI Standard Z87.1) and
protective clothing when removing slag.
Hot, flying debris can cause personal
injury to anyone in the area.
After completing the weld, wait for the
welded sections to cool. A protective
coating called slag now covers the weld
!
WARNING
bead which prevents contaminants in
the air from reacting with the molten
metal. Once the weld cools to the point
that it is no longer glowing red, the slag
can be removed. Removal is done with a
chipping hammer. Lightly tap the slag
with the hammer and break it loose
from the weld bead. The final clean-up is
done with a wire brush. When making
multiple weld passes, remove the slag
before each pass.
WELDING POSITIONS
Four basic welding positions can be used;
flat, horizontal, vertical, and overhead.
Welding in the flat position is easier than
any of the others because welding speed
can be increased, the molten metal has
less tendency to run, better penetration
can be achieved, and the work is less
fatiguing. Welding is performed with
the wire at a 45º travel angle and 45º
work angle.
Other positions require different
techniques such as a weaving pass,
circular pass, and jogging. A higher skill
level is required to complete these welds.
Overhead welding is the least desirable
position as it is the most difficult and
dangerous. Heat setting and wire
selection will vary depending upon the
position.
All work should be performed in the flat
position if possible. For specific
applications, consult an arc welding
technical manual.
WELD PASSES
Sometimes more then one pass is
necessary to fill the joint. The root pass is
first, followed by filler passes and the
cover pass (See Fig. 14). If the pieces are
thick, it may be necessary to bevel the
edges that are joined at a 60º angle.
Remember to remove the slag before
each pass.
E
-
7 0 T
-
GS
Weld strength, times
10,000 pounds per
square inch
Welding positions (0
for flat or horizontal,
1 for any position)
Tubular flux core wire
Flux type
AWS E71T-GS or E71T-11 is
recommended for these welders.
Travel Angle
Work Angle
5º - 45º
5º - 45º
Figure 13 - Weld Angle
Figure 14 - Fillet Welds (60˚ Bevel)
Models WF1800, WF1900 and WF2000
Welding Guidelines
(Continued)
Cover
Root
Filler
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