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LEARNING TO STICK WELD
2
LEARNING TO STICK WELD
No one can learn to weld simply by reading about it.
Skill comes only with practice. The following pages
will help the inexperienced welder to understand
welding and develop his skill. For more detailed infor-
mation order a copy of (“New Lessons in Arc Welding”
available from the James F. Lincoln Foundation).
The Arc-Welding Circuit
The operator’s knowledge of arc welding must go
beyond the arc itself. He must know how to control the
arc, and this requires a knowledge of the welding cir-
cuit and the equipment that provides the electric cur-
rent used in the arc. Figure 1 is a diagram of the weld-
ing circuit. The circuit begins where the electrode
cable is attached to the welding machine and ends
where the work cable is attached to the welding
machine. Current flows through the electrode cable to
the electrode holder, through the holder to the elec-
trode and across the arc. On the work side of the arc,
the current flows through base metal to the work cable
and back to the welding machine. The circuit must be
complete for the current to flow. To weld, the work
clamp must be tightly connected to clean base metal.
Remove paint, rust, etc. as necessary to get a good
connection. Connect the work clamp as close as pos-
sible to the area you wish to weld. Avoid allowing the
welding circuit to pass through hinges, bearings, elec-
tronic components or similar devices that can be dam-
aged.
This arc-welding circuit has a voltage output of up to
79 volts which can shock.
The electric arc is made between the work and the tip
end of a small metal wire, the electrode, which is
clamped in a holder and the holder is held by the
welder.
The serviceability of a product or structure utiliz-
ing this type of information is and must be the
sole responsibility of the builder/user. Many vari-
ables beyond the control of The Lincoln Electric
Company affect the results obtained in applying
this type of information. These variables include,
but are not limited to, welding procedure, plate
chemistry and temperature, weldment design, fab-
rication methods and service requirements.
WARNING
ELECTRIC SHOCK can kill.
Carefully review the ARC WELDING
SAFETY PRECAUTIONS at the beginning
of your Operator’s Manual.
------------------------------------------------------------------------------------------
A gap is made in the welding circuit (see Figure 1) by
holding the tip of the electrode 1/16-1/8” away from
the work or base metal being welded. The electric arc
is established in this gap and is held and moved along
the joint to be welded, melting the metal as it is
moved.
Arc welding is a manual skill requiring a steady hand,
good physical condition, and good eyesight. The oper-
ator controls the welding arc and, therefore, the quali-
ty of the weld made .
What Happens in the Arc?
Figure 2 illustrates the action that takes place in the
electric arc. It closely resembles what is actually seen
during welding.
The “arc stream’’ is seen in the middle of the picture.
This is the electric arc created by the electric current
flowing through the space between the end of the
electrode and the work. The temperature of this arc is
about 6000°F. (3315°C.), which is more than enough
to melt metal. The arc is very bright, as well as hot,
and cannot be looked at with the naked eye without
risking painful injury. The very dark lens, specifically
designed for arc welding, must be used with the hand
or face shield whenever viewing the arc.
The arc melts the base metal and actually digs into it,
much as the water through a nozzle on a garden hose
digs into the earth. The molten metal forms a molten
pool or crater and tends to flow away from the arc. As
it moves away from the arc, it cools and solidifies. A
slag forms on top of the weld to protect it during cool-
ing.
To electrical
(earth) ground.
FIGURE 1—The welding circuit for Shielded Metal
Arc Welding(SMAW)
.
FIGURE 2—The welding arc.