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-125 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-125 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 CO2 and Argon (75-80%) gas and 0.025” (0 6 mm) diameter Lincoln L-56 mild-steel welding wire [supplied on 121/2 Ib (6 kg) spools]. For 14 gauge (2,0 mm) and thinner CO2, or blended gas is acceptable. A mixed gas consisting of 75 to 80% Argon and 20 to 25% CO2 is recommended for weld- ing 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 on 10 Ib (4,5 kg) spools. This electrode can be used for all position welding of 20 gauge through 5/16” (1,0 – 8,0 mm) thick steel [multi- ple passes are required for 1/4” and 5/16” (6,0 and 8,0 mm)].
WARNING
Use of the GMAW process with the SP-125 Plus on thicker materials than recommended 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.
The SP-125 Plus is suitable for .035" Aluminum wire and .030" stainless wire. Refer to Table B.1 for Recommended Procedure Settings. Aluminum wire requires K663-1 Aluminum Welding kit. See ACCES- SORIES section.
CAUTION
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.
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TABLE B.1 — SP-125 Plus Welding Procedures
| Welding | Shielding | | | | |
Process | Wire | Gas | 16 ga | 14 ga | 12 ga | 10 ga |
MIG DC+ | .035 Dia | 100% Argon | D-4.5 | H-6.5 | H-6.5 | J-7.5 |
| 4043 Aluminum | | | | | |
| Wire | | | | | |
MIG DC+ | .035 Dia | 100% Argon | C-5.5 | D-6 | G-8.5 | H-9.5 |
| 5356 Aluminum | | | | | |
| Wire | | | | | |
MIG DC+ | .030 Dia | 98% Argon/ | D-3 | F-4 | J-5 | J-6.5 |
| 308L Stainless | 2% Oxygen | | | | |
| Steel Wire | | | | | |
| | | | | | |
CHANGING MACHINE OVER TO FEED OTHER WIRE SIZES
The SP-125 Plus is shipped from the factory ready to feed 0.023-0.025” (0,6 mm) diameter wire. To operate the SP-125 Plus with other sizes of wire, it is neces- sary to change the contact tip and change the drive roll over to other sizes. Refer to Changing the Contact Tip and Changing the Drive Roll, in the MAINTE- NANCE section, for specific information on these pro- cedures.
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.
