Wire Feed Arc Welder
8
Welding Guidelines
(Continued)
WELD ANGLE
Weld angle is the angle at which the
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
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. 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
torch 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. 11). 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
(FLUX-CORED WIRE ONLY)
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
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.
TRAVEL ANGLE
WORK ANGLE
5º - 45º
5º - 45º
Figure 10 - Weld Angle
Normal Heat,
Wire Speed,
Travel Speed
Heat Too Low
Heat Too High
Wire Speed
Too Fast
Wire Speed Too Slow
Travel Speed
Too Slow
Travel Speed
Too Fast
Base
Metal
Figure 11 - Weld Appearance
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