12
twist the nozzle like a screw to install or remove as
it grips the nozzle tightly. There is a special retain-
ing spring under the nozzle that acts as a thread.
This feature allows you to position the nozzle in
order to vary the depth of the contact tip for differ-
ent welding applications.
4)
Shielding gas selection and use.
For MIG operation,
selection of the proper shielding gas is important.
Remember, each shielding gas mixture and filler
metal thickness will require a different setting of
voltage and amps.
A 75/25 (75% Argon/25%CO2)
mixture is recommended for general purpose steel
welding. This yields the best results in most cir-
cumstances. To reduce spatter further, other
blends of Ar/CO2 with higher percentages of Argon
(a true inert gas) may be used. The puddle may be
difficult to control and cold lap may occur if the mix
is over 85% Argon, especially if used in out of posi-
tion welds. Generally, when there is a higher per-
centage of Argon present in the mix, the cost of the
mix will be greater. Though less desirable, 100%
CO2 may also be used. Greater penetration with a
narrower bead profile can be achieved with 100%
CO2. However, extra spatter, smoke and oxidation
will be noticed. CO2 is not a a true inert gas so it
can impart a dull gray, and even flaky appearance to
the weld as it interacts with the molten metal. If
100% CO2 is used, regularly check to ensure the
regulator is not freezing up. CO2 offers a cheaper
option but losses in transfer efficiency (amount of
metal actually deposited versus total amount con-
sumed) and extra time spent for cleaning spatter
may negate initial cost savings. For Stainless, a
commercial Tri
-
mix of gas is generally used for
short circuit transfer. This is usually a proprietary %
blend of Argon, Helium, and CO2. Consult with your
local welding supply store. For aluminum, 100%
Argon must be used.
Using this welder for steel/
stainless spray transfer and use with spray transfer
MIG gases is not recommended due to the high
heat generated.
However, Aluminum spray transfer
is performed at a lower transitiona amperage and is
not an issue with this unit and in fact is the best way
to achieve quality Aluminum welds with MIG.
5)
Regulator and shielding gas flow adjustment.
NOTE: Regulators are supplied in CFH for USA
(LPM in Europe and other countries). Please note
which has been provided before starting to weld for
future reference.
The regulator should always be
mounted nearly vertical if not with a slight tilt back
(for safety) so that the ball may float free.
Always
stand to the opposite side of the regulator and
slowly open the regulator with the front and top of
the regulator facing away from you.
Gas flow re-
quirements vary in MIG greatly and a lot depends
upon the environment. More gas will be required in
open/drafty areas. To avoid wasting shielding gas,
perform several preliminary test welds. To adjust,
decrease gas flow until the weld begins to bubble
and exhibit porosity. Gradually increase the gas flow
until the bubbles disappears completely. Crack the
adjustment on the regulator an small additional
amount to ensure full gas coverage. This process
will reduce waste and help ensure you are not intro-
ducing oxygen into the weld. As the pressure drops
within the cylinder readjustment may be necessary.
6)
MIG polarity.
When using solid MIG wire, the po-
larity should always be electrode positive. This
means the torch should always be connected to the
positive (+) terminal when welding with solid wire.
To check this, open the cover, and inspect the
heavy power cable that runs from the front end of
the wire feeder to the bolted terminals on the center
divider wall that are marked either with a positive
(+) sign or a negative (
-
) sign. The cable should be
screwed down to the terminal marked with the (+)
sign for solid wire. For flux core, most (but not all)
manufacturers of flux core wire specify the use of
negative (
-
) polarity. Consult the manufacturer
’
s
recommendations regarding flux core or dual shield
wire polarity before installation. If negative polarity
is required, swap the feeder cable to the negative
terminal. Always make sure the terminal screw is
fully tightened. Do not over tighten the terminal or it
may strip out the terminal threads.
If, after switch-
ing between solid and flux core wire, an erratic arc
is noticed, double check the polarity. This is a
commonly overlooked part of the changeover pro-
cedure.
7)
Volt and Amp adjustment.
The welder features infi-
nite adjustment of voltage and wire feed speed
within each range. Wire speed adjustment is direct-
ly related to amp output and the terms are generally
used interchangeably. As wire speed increases so
does amperage and vice versa. In many welding
charts and calculators, you may find actual amper-
age settings rather than a wire speed setting. Am-
perage output also depends upon the diameter of
the wire as well. Both volts and amps are calibrated
in numbers ranging from 1
-
10 with infinite adjust-
ment possibility between each number. These are
relative numbers and are used only as a reference
when repeating the same or similar setup. If helpful
for setting up the unit, the numbers 1
-
10 can be
thought of as representing 10%
-
100% of full output
for either voltage or wire speed. For each wire di-
ameter, most users will find 3 to 5 settings that will
fit their welding style and applications but often the
ability to fine tune these settings for specific appli-
cations will be needed.
At first, some experimen-
tation will be necessary.
The following method of
setting up wires peed and voltage is commonly
used by professionals in the industry to setup al-
most any type MIG. When setting up welding pa-
rameters, set the wire speed halfway then begin to
lower the voltage until it begins to cold feed into the
metal (also referred to as stubbing). Note the point
where it begins to do so. Next, raise the voltage
until the puddle becomes hot and the arc seems
Introduction and Specifications
Section 1
