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 affect the speed of travel
necessary for completing a good weld (See Figure 7). 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. For Aluminum, travel speed is typically faster.
Electrode Extension
Electrode extension (or electrode stick-out) is the distance between the end of the contact tip and and the
end of the welding wire. The recommended electrode extension is from 1/4 to 1/2 in (6 to 13 mm). If the
electrode extension is too long, welding current will be reduced and the bead will be high and narrow with
less penetration.
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.
All work should be performed in the flat position if possible. For
specific applications, consult an arc welding technical manual.
Weld Passes
Sometimes more than one pass is necessary to fill the joint. The
root pass is first, followed by filler passes and the cover pass. 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 for the FCAW process.
Figure 8 - Weld Passes
Figure 9 - Multiple Weld Passes
13
13
Cover
Filler
Root