Tig Operation And Theory - Everlast Lightning MTS 225 Operator's Manual

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Section 3
General Setup. The process to set up the welder for
the basic TIG mode is much less involved than for
basic MIG. TIG voltage is not conventionally adjusta-
ble and is a product of the arc length. This is not to
say voltage is not important to TIG welding, but it is
not something that can be adjusted on the unit. In
practical terms, voltage is not a concern to the user as
it is self regulating. Amperage however, is adjustable.
Setting up Amperage correctly for TIG is different as
there is no "sound" to listen for. But for each given
thickness of metal, there is an acceptable range of
adjustment for TIG. Traditionally, a general rule of
thumb for TIG setup is to set approximately 1 amp for
every .001" of metal thickness. For modern inverter
technology, that may be too many amps in all but the
thickest weld material, particularly for a DC inverter
TIG welder such as this one. In many cases, you will
only need to use 75% to 80% of that amperage. But
if you are setting up the unit to use a foot pedal, use
the rule of thumb to begin with as you can always
back off the amperage as you are welding by letting
up some on the foot pedal. Much of the information in
the "Basic MIG Operation" guide in this manual is
useful and applicable for TIG welding. Pay particular
attention to the subsections about metal cleaning and
multiple pass welds. If needed, there are several
online TIG apps and calculators that you can give you
starting points for welding almost any thickness as
well as general settings for tungsten size, and gas
flow rates. But more importantly, utilizing the Power-
Set mode of this unit will eliminate having to "guess"
at proper settings for your application.
Use the information on the following pages to help
guide you through arc starting and tungsten prepara-
tion.
Welding. If you are new to TIG welding, it's important
that you understand that TIG welding is much slower
than MIG or Stick welding. It requires patience and
steady practice to become proficient at TIG welding.
However, most people can achieve some level of pro-
ficiency at TIG welding if they are patient, and are will-
ing to analyze and adjust the way they are welding.
To start welding, set the amps desired for the metal
thickness you are about to weld. Before striking the
arc, make sure the shielding gas is on, and properly

TIG OPERATION AND THEORY

set. Also adjust your Tungsten stick-out to about 1/8"
and gas flow rate to approximately 16-20 CFH to
begin. Then follow the TIG arc starting methods on
found later in the manual. Once the arc is started,
keep a loose but sure grip on the TIG torch to prevent
cramping. An underhand hold is good, similar to the
way a pencil is held. A foregrip may be used as well,
but offers less fine control at the beginning and re-
quires more propping to keep the torch steady.
Practice running slowly without filler metal first.
Keep the torch head inclined away from the direction
of travel, so the Tungsten stays just above the puddle,
pointed toward the front of the puddle. Move slowly
and methodically, gauging your forward movement to
make sure it is steady and paced. Imagine a thick
coin is able to be placed between the tip of the Tung-
sten and the weld puddle. As your skill progresses,
you will want to add filler wire to your practice. The
angle created between the filler rod should be about
90 degrees. In between the filler rod and the torch,
your head should be placed so that you can clearly
see the arc. Feed the filler rod into the front edge of
the puddle, being careful not to place the filler on top
of the Tungsten, or touch it in any way. If you dip the
tungsten into the filler rod or into the puddle, you
must stop and regrind it or the arc will become unsta-
ble. Feed the filler in regular, timed dips as the pud-
dle forms. If you need, count out loud as you time
your dips until you can do it without thinking. As you
proceed to dip your rod into the edge of the puddle,
keep the rod close to the puddle, within the gas cone.
If the filler metal starts to melt before you dip, you
have it too close, or you have the rod inclined too
much so that heat is being directed too far in front of
the puddle. As you add the filler, be sure to pause
momentarily with the forward travel of the torch. If
desired, a tiny back step motion may be used to im-
prove weld appearance. There are other ways to add
filler and to create a sound weld. You can keep the
filler wire in the puddle, with the rod laying in a flatter
profile and weld. As the torch moves forward and the
rod melts, the filler can be slid, with gentle pressure,
into the puddle as needed to fill the weld. This is
known as the Lay-Wire technique. Another method of
welding has more to do with torch manipulation than
it does filler addition, is called walking the cup. The
cup is rested on the metal while the torch head is os-
85
Basic Theory and Function

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