Everlast POWER MTS 221STi, Руководство оператора

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Special Notes Concerning Operation.
1. Shielding Gas Selection for MIG and TIG.
While welding aluminum with the Spool
gun or MIG gun you must use 100% Ar-
gon. You cannot use a mix as you would
with steel or stainless. For Steel or Stain-
less, there are a variety of gases that are
used. The type of gas used with Steel or
Stainless depends upon whether you are
using short
- circuit transfer, or spray trans-
fer. In general, the best general gases
mixes for welding with Steel are gas mixes
that are less than 80% Argon with the bal-
ance CO2, or CO2 and O2. A Common
mix, usually referred to as a C25 mix,
(75% Argon, and 25% CO2 ) is typically
the most economical of the steel gas mix-
es. 100% CO2 is permissible as well, and
is the most economical option for steel
welding. However, more spatter and less
aesthetic welds will result, requiring more
labor during cleanup. For Spray
- Transfer,
or, gas mixes with greater than 80% Ar-
gon content is recommended. Common
spray transfer gases for steel are 90/10
Ar/CO2, 95/5 Ar/CO2, 98/2, Ar/CO2 or
98/2 Ar/CO2. Some welding suppliers
also suggest Trimixes of Ar/CO2/O2 for
spray transfer or pulse spray transfer
welding of Steel. For Stainless, there are
several recommendations for welding
with stainless whether in Short
- circuit
transfer. But there is mixed consensus on
the best gas for use for short
- circuit,
Pulsed - spray transfer and Axial - Spray
transfer. Stainless develops a more slug-
gish puddle and wet is not as smooth and
easy flowing as steel or aluminum. 98/2
Ar/CO2, or 98/2 Ar O2 is often recom-
mended for spray
- transfer welding when
economy is needed. In fact other less Ar-
gon rich blends are sometimes recom-
mended, and it is possible. But when
more CO2 is added, the rust resistance of
stainless goes down due to the added car-
bon content. Ideally, there are several Tri
-
gas mixes out there that are well suited to
welding stainless. These include the addi-
tion of Helium to the mix as either the pri-
mary or secondary component of the mix.
The Helium tends to help improve wet
- in
and fluidity of the puddle, but a higher
voltage may be needed to weld if the Heli-
um content is too high. It is also much
more expensive. Welds made with Tri
- gas
mixes tend to hold their rust resistance
better. But to reduce the heat that is put
into the weld , and reduce warping, there
are stainless tri–
gas mixes on the market
that have a content of approximately 35%
or lower Helium. These still are great for
preserving rust resistance of the stainless
alloys. Wet
- in is still excellent and cost is
much lower than higher Helium content
blends. While welding in any of the TIG
modes you must also weld use 100% Ar-
gon for any metal type. (This unit is not
designed to weld aluminum with TIG, but
if it could 100% Argon would still be used.)
In some cases, blends of Ar/He may be
used for TIG for welding thicker metal
thicknesses, but the cost to do so is quite
high as He/Argon mixes are expensive by
comparison.
2. MIG Welding Aluminum. While welding
aluminum with the Spool gun or MIG gun
you must use the next size up tip or a spe-
cial oversize tip for the wire because the
heat will cause the aluminum wire to
swell and it will either drag or seize in the
tip, due to the dissimilar expansion rates
of the copper tip and aluminum wire. If
you are suffering burn backs while weld-
ing Aluminum (and in some cases stain-
less), change to a larger tip, and reduce
burn back time. While welding aluminum
with the MIG process, best results are
Basic Theory and Function
Section 3