Everlast PowerMTS 251Si Operator's Manual page 44

Section 3
puddle development and behavior. In-
creasing arc force to 90% or more in stain-
less applications will actually help to re-
duce puddle sluggishness and increase
travel speed. For aluminum, the induct-
ance settings are dependent upon the filler
wire type.
5. MIG Gas. While MIG gas doesn't directly
control pulse, it does have a significant
effect on pulse settings. Gas type and flow
rate do have profound effects on heat de-
velopment in a puddle. If you desire to use
the pulse-spray mode, you will need to se-
lect a MIG gas blend that is greater than
80% Argon (90% or greater is preferred),
with the balance being CO2, or O2 if weld-
ing steel. Aluminum will always require
100% argon regardless of whether stand-
ard, synergic or pulse mode selected. As
for stainless steel types, several gases may
be selected, but be sure they are rated for
the type mode you wish to perform ( Axial-
pulse-spray, short circuit, or short circuit
pulse.) A standard Tri-Mix of helium (65%
or greater), with balance argon and CO2 or
blends of 98/2 Ar/O2, or 98/2 Ar/CO2
great for general purpose welding of stain-
less. But for welding thin steels a trimix
with some helium, usually around 35% will
be the best bet. The lower Helium per-
centage reduces the heat of the arc with-
out compromising the shielding properties
needed in stainless to prevent sugaring
and granular development. The lower He-
lium trimix is much better for thin gauges
of heat sensitive stainless while using
pulse. This type mix can be found in a pro-
prietary "Gold" trimix blend recommended
for welding stainless or can be locally
mixed. This is also more economical to use
since the higher helium level version of
PULSE MIG OPERATION
Basic Theory and Function
trimix is considerably more expensive.
PULSE WORKSHEETS
Use the following worksheets to save and
record your pulse settings for different metals
and wire diameters. Or, you may use it to
create your own additional spread sheet of
settings. Consider using the program
memory to save your pulse settings. This is
important to ensure rapid setup and repeata-
bility of detailed weld parameters of the
pulse. Once the settings have been saved,
record the basic settings in the work sheet in
case you accidentally save over a favorite
program. The following pages can also be
used to record settings that you have tried
that didn't work so that you can help deter-
mine a pattern of settings that are most use-
ful to you.
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