Lincoln Electric IM790 SP-175 Plus - Manual (Page 19)

B-6
B-6 OPERATION
9. To stop welding, release the gun trigger and then
pull the gun away from the work after the arc goes
out.
10. When no more welding is to be done, close valve
on gas cylinder (if used), momentarily operate gun
trigger to release gas pressure, and turn off the
SP-175 Plus.
Cleaning Tip And Nozzle
Clean the contact tip and nozzle to avoid arc bridging
between the nozzle and contact tip which can result in
a shorted nozzle, poor welds and an overheated gun.
Hint: Anti-stick spray or gel, available from a welding
supply distributor, may reduce buildup and aid in spat-
ter removal.
PROCESS GUIDELINES
The SP-175 Plus can be used for welding mild steel
using the GMAW, single pass, process which requires
a supply of shielding gas or it can be used for the self
shielded, Innershield electrode process.
The recommended gas and electrode for GMAW is
welding grade mixed CO
2
and Argon (75-80%) gas
and 0.025 ” (0 6 mm) diameter Lincoln Super Arc L-56
mild-steel welding wire. For 14 gauge (2,0 mm) and
thinner CO
2
, or blended gas is acceptable. A mixed
gas consisting of 75 to 80% Argon and 20 to 25% CO
2
is recommended for welding on heavier gauge [12
gauge (2,5 mm) for example] steel.
The recommended electrode for the self-shielded
process is 0.035
” (0,9 mm) diameter Lincoln
Innershield NR-211-MP. This electrode can be used
for all position welding of 20 gauge through 5/16
” (1,0
– 8,0 mm) thick steel [multiple passes are required for
1/4 ” and 5/16 ” (6,0 and 8,0 mm)].
The SP-175 Plus is suitable for .035" Aluminum wire
and .030"-.035
” stainless wire. Refer to Table B.1 for
Recommended Procedure Settings. Aluminum wire
requires an Aluminum Welding kit. See ACCES-
SORIES section.
It is important when changing between welding
with steel wire and aluminum to exchange feeding
components due to the lubricant applied to steel
wire. Failure to do so may result in contaminated
welds when welding aluminum.
------------------------------------------------------------------------
TABLE B.1 — SP-175 Plus Welding Procedures
* Test assembly preheated to 250 ° F.
CHANGING MACHINE OVER TO
FEED OTHER WIRE SIZES
The SP-175 Plus is shipped from the factory with a
gun liner ready to feed 0.023-0.035
” (0.6-0.9 mm)
diameter wire. The contact tip is 0.025 ” (0.6 mm) and
the drive roll is set for 0.023 ” -0.025 ” (0.6 mm). To
operate the SP-175 Plus with other sizes of wire, it
maybe necessary to change the contact tip, and Gun
Liner Configuration. Refer to the maintenance section
for component configuration and replacement proce-
dures
WELDING WITH FCAW (Innershield)
Welding with Innershield requires an Innershield
Welding Kit. A gasless nozzle is provided in the
Innershield Welding Kit. When using Innershield elec-
trode, installing the gasless nozzle will improve visibili-
ty of the arc and protect the gas diffuser from weld
spatter. Additionally included is a gun cable liner to
permit proper feeding of .035
” (0,9 mm) Innershield
wire. Refer to the ACCESSORIES section for details
on obtaining this kit.
WARNING
Use of the GMAW process with the SP-175 Plus on
thicker materials than 5/16
” (8.0 mm) may result in
poor welds. The welds may “ look ” good, but may
just be “ sitting ” on top of the plate. This is called
“ cold casting ” and will result in weld failure.
CAUTION
SP-175 PLUS
Shielding Voltage/Wire Speed
Process Welding Wire Gas 22 ga 16 ga 12 ga 1/8 ” 3/16 ” 1/4 ”
.035 Dia(0.9mm 100% Argon B-5 B-7 E-9 G-9 I-9 J-10*
4043 Aluminum
Wire
MIG DC+
16 ga 14 ga 12 ga 10 ga
.030 Dia 98% Argon/ A-3 C-6 D-7.5 D-7.5
308L Stainless 2% Oxygen
Steel Wire