of the weld, the travel angle is called a "drag" angle. If
and gas hose across your shoulder to ensure free
the gun is pointed ahead toward the end of the weld, the
movement of the welding torch. Hold the torch close to,
travel angle is called a "push" angle.
but not touching, the work piece. Lower your helmet
and squeeze the trigger on the torch. Squeezing the
When the gun is ahead of the weld, it is referred to
trigger starts the flow of shielding gas and energizes the
as pulling the weld metal. If the gun is behind the weld,
welding circuit. The wire-feed motor is not energized
it is referred to as pushing the metal. The pulling
until the wire electrode comes in contact with the work
technique is usually best for light gauge metals and the
piece. Move the torch toward the work, touching the
pushing technique for heavy materials.
wire electrode to the work with a sideways scratching
Generally, the penetration of beads deposited with
motion, as shown in view A of figure 6-48. To prevent
the pulling technique is greater than with the pushing
sticking, it is necessary to pull the gun back quickly,
technique. Furthermore, since the welder can see the
about 1/2 inch, the instant contact is made between the
weld crater easier in a pulling action, he/she can
wire electrode and the work piece. The arc will strike as
produce high quality welds more consistently. On the
soon as contact is made, and the wire-feed motor will
other hand, pushing permits the use of higher welding
feed the wire automatically as long as the trigger is
speeds and produces less penetrating and wider welds.
held.
To break the arc, just release the trigger. This
WELDING SAFETY PRECAUTIONS
breaks the welding circuit and also de-energizes the
wire-feed motor. If the wire electrode sticks to the work
Accidents frequently occur in welding operations,
when it strikes the arc, or at any time during welding,
and in many instances, they result in serious injury to
release the trigger and clip the wire with a pair of pliers
the welder or other personnel working in the immediate
or side cutters.
area. What many welders fail to realize is that accidents
often occur NOT because of a lack of protective
A properly established arc has a soft, sizzling
equipment, but because of carelessness, lack of
sound. The arc itself is about 1/4 inch long, or about
knowledge, and the misuse of available equipment.
one-half the distance between the gun nozzle and the
work. When the arc does not sound right, you may need
You, the welder, should have a thorough
to adjust the wire-feed control dial or the welding
KNOWLEDGE of safety precautions relating to the
machine itself. For example, a loud, crackling sound
job. But that is not all. You should also consider it a
indicates that the arc is too short and the wire-feed
responsibility to carefully OBSERVE the applicable
speed is too fast. Correct this by moving the wire-feed
safety precautions. In welding, being careless can cause
speed dial slightly counterclockwise. This decreases
serious injury not only to yourself, but to others as well.
wire-feed speed and increases arc length. A clockwise
Bear in mind that safety precautions for the
movement of the dial has the opposite effect. With
operation of welding equipment vary considerably
experience, you will soon be able to recognize the
because of the different types of equipment involved.
sound of the proper length of arc to use.
Therefore, only general precautions on operating metal
The proper position of the welding torch and
arc-welding equipment are given here. For specific
material is important. The flat position of the material is
instructions on the operation, maintenance, and care of
preferred for most joints because this position improves
individual
equipment,
use
the
equipment
the molten metal flow, bead contour, and gives better
manufacturer's instruction manual as a guide.
gas protection.
In regard to general precautions, know your
The alignment of the welding wire in relation to the
equipment and how to operate it. Use only approved
joint is very important. The welding wire should be on
welding equipment, and see that it is kept in good, clean
the center line of the joint if the pieces to be joined are
condition. Before you start to work, make sure that the
of equal thickness. If the pieces are unequal in
welding machine frame is grounded, that neither
thickness, the wire may be moved toward the thicker
terminal of the welding generator is bonded to the
piece.
frame, and that all electrical connections are securely
made. The ground connection must be attached firmly
Correct work and travel angles are necessary for
to the work, not merely laid loosely upon it.
correct bead formations. The travel angle may be a push
angle or a drag angle, depending upon the position of
Keep welding cables dry and free of oil or grease.
the gun. If the gun is angled back toward the beginning
Keep cables in good condition, and, at all times, take
6-34
