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5.
When you are sure that you can hold the correct electrical
stickout, with a smooth "crackling" arc start moving. Look at
the molten puddle constantly, and look at the "ridge" where
the metal solidifies.
6.
Run beads on a flat plate. Run them parallel to the top edge
(the edge farthest away from you). This gives you practice
in running straight welds, and also gives you an easy way
to check your progress. The 10th weld will look
considerably better than the first weld. By constantly
checking on your mistakes and your progress, welding will
soon be a matter of routine.
5.8 Machine Set Up for the GMAW (MIG)
Process and Gas Shielded GCAW Processes
1.
The REDI-MIG 455 Remote comes ready for welding using
the MIG process.
2.
See the Procedure Welding Guide on the inside of wire
feed section door for information on setting the controls.
3.
Set the "Voltage" and "Wire Speed" controls to the settings
suggested on the Procedure Welding Guide for the welding
wire and base metal thickness being used. '
4.
Check that the polarity is correct for the welding wire being
used. Set the polarity for DC(+) when welding with the
GMAW (MIG) process. See Section 1.5 for instructions for
changing polarity.
5.
Check that the gas nozzle and proper size liner and contact
tip are being used and that the gas supply is turned on. Set
for 7 to 10 L/min. under normal conditions, increase to as
high as 17 L/min. under drafty (slightly windy) conditions.
6.
Connect work clamp to metal to be welded. Work clamp
must make good electrical contact to the work piece. The
work piece must also be grounded as stated in the "Arc
Welding Safety Precautions" at the beginning of this
manual.
Figure 8
5.9 Welding Techniques for the GMAW (MIG)
Process
Four simple manipulations are of prime importance when
welding. With complete mastery of the four, welding will be
easy. They are as follows:
1. The Correct Welding Position
Figure 8 illustrates the correct welding position for right
handed people. (For left handed people, it is the
opposite.)
When GMAW (MIG) welding on sheet metal, it is
important to use the "forehand" push technique.
Hold the gun (of the gun and cable assembly) in your
right hand and hold the shield with your left hand. (Left
handers simply do the opposite.) Weld from right to left
(if you are right handed). This results in a colder weld
and has less tendency for burn through.
IMA 603
When using an open arc process, it Is necessary to use
correct eye, head and body protection.
Protect yourself and others, read "ARC RAYS can burn" at
the front of this manual.
2. The Correct Way To Strike An Arc
1. Be sure the work clamp makes good electrical
2. Position gun over joint. End of wire may be lightly
3. Position face shield to protect face and eyes, close
4. To stop welding, release the gun trigger and pull the
5. A ball may form at the tip end of the wire after
6. When no more welding is to be done, close the valve
Figure 9
3. The Correct Electrical Stickout (ESO)
The electrical stickout (ESO) is the distance from the
end of the contact tip to the end of the wire. See Figure
9.
Once the arc has been established, maintaining the
correct ESO becomes extremely important. The ESO
should be approximately 10 to 12 mm long.
The easiest way to tell whether the ESO is the correct
length is by listening to its sound. The correct ESO has
a distinctive "crackling" sound, very much like eggs
frying in a pan. A long ESO has a hollow, blowing or
hissing sound. If the ESO is too short, you may stick the
contact tip or nozzle to the weld puddle and/or fuse the
wire to the contact tip.
4. The Correct Welding Speed
The important thing to watch while welding is the puddle
of molten metal right behind the arc. See Figure 10. Do
not watch the arc itself. It is the appearance of the
puddle and the ridge where the molten puddle solidifies
that indicates correct welding speed. The ridge should
be approximately 10 mm behind the wire electrode.
Most beginners tend to weld too fast, resulting in a thin,
uneven, "wormy" looking bead. They are not watching
the molten metal.
REDI-MIG 455 Remote
ARC RAYS can burn
eyes and skin
contact to the work.
touching the work.
gun trigger, and begin welding. Hold the gun so that
the contact tip to work distance is about 10 - 12 mm.
gun away from the work after the arc goes out.
welding. For easier restrikes, the ball may be
removed by feeding out a few inches of wire and
cutting off the end of the wire with wire cutters.
on the gas cylinder, momentarily operate the gun
trigger to release gas pressure, then turn off the
machine.
Page 19
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