6. When the weld is complete, lift the Gun and
welding wire clearly away from any grounded
object, and turn the powers switch off.
TIG WELDING
1. Turn the Current Adjustment Knob to meet
the needs of the job.
2. Move the Model Selector Switch to "MIG".
3. Put the metal to be welded on the metal
weeding table. Ensure the metals to be welded
are clean, so good welding efficiency can be
promised.
4. Hold the Trigger down and tilt the torch for-
ward. Keep a constant distance between the
torch and the workpiece but do not contact it.
5. Stroke the workpiece lightly to ignite the
arc. Do not strike like a match. Never tap the
electrode wire to ignite the arc; it will damage
the electrode.
6. When the arc ignites, tilt the electrode for-
ward and hold it near the workpiece.
ARC (STICK)
1. Turn the Current Adjustment Knob to meet
the needs of the job.
2. Move the Stick or TIG Switch to "TIG"
3. Connect the Electrode Clamp and Cable to
the torch control connector (as 7 shown on
page 9 and twist to lock in place.
4. Plug the cable of the Grounding Clamp into
the DC ground connector and secure the clamp
to a clean, exposed metal part of the work-
piece.
5. Place the metal portion of the welding rod
inside the jaws of the Electrode Clamp. Weld-
ing rod types vary for welding different metals.
NOTE: If too much current is drawn from the
welder; the Thermal Overload protector will
activate, the Overload indicator will light, and
the welder will turn off until it cools down. It
will automatically reset.
GAS METAL ARC
Gas metal arc welding (GMAW), sometimes re-
ferred to by its subtypes metal inert gas (MIG)
welding or metal active gas (MAG) welding,
is a semi-automatic or automatic arc welding
process in which a continuous and consum-
able wire electrode and a shielding gas are
fed through a welding gun. A constant volt-
age, direct current power source is most com-
E N G L I S H •
monly used with GMAW, but constant current
systems, as well as alternating current, can be
used. There are four primary methods of metal
transfer in GMAW, called globular, short-circu-
iting, spray, and pulsed-spray, each of which
has distinct properties and corresponding ad-
vantages and limitations.
Welding gun and wire feed unit
The typical GMAW welding gun has a num-
ber of key parts—a control switch, a contact
tip, a power cable, a gas nozzle, an electrode
conduit and liner, and a gas hose. The control
switch, or trigger, when pressed by the opera-
tor, initiates the wire feed, electric power, and
the shielding gas flow, causing an electric arc
to be struck. The contact tip, normally made
of copper and sometimes chemically treated
to reduce spatter, is connected to the welding
power source through the power cable and
transmits the electrical energy to the electrode
while directing it to the weld area. It must be
firmly secured and properly sized, since it must
allow the passage of the electrode while main-
taining an electrical contact.
Before arriving at the contact tip, the wire is
protected and guided by the electrode conduit
and liner, which help prevent buckling and
maintain an uninterrupted wire feed. The gas
nozzle is used to evenly direct the shielding gas
into the welding zone—if the flow is inconsis-
tent, it may not provide adequate protection
of the weld area. Larger nozzles provide great-
er shielding gas flow, which is useful for high
current welding operations, in which the size
of the molten weld pool is increased. The gas
is supplied to the nozzle through a gas hose,
which is connected to the tanks of shielding
gas. Sometimes, a water hose is also built into
the welding gun, cooling the gun in high heat
operations. The wire feed unit supplies the
electrode to the work, driving it through the
conduit and on to the contact tip. Most models
provide the wire at a constant feed rate, but
more advanced machines can vary the feed
rate in response to the arc length and voltage.
Some wire feeders can reach feed rates as high
as 30.5 m/min (1200 in/min), but feed rates for
semiautomatic GMAW typically range from 2
to 10 m/min (75–400 in/min)
U se r's m a n ua l
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