Lincoln Electric IM784 manual Process Guidelines, Making a Weld, Cleaning Tip And Nozzle

B-5 OPERATION B-5

FIGURE B.6

Contact Tip

Electrode

3/8”-1/2”(10-12mm)Contact Tip to Work Distance(CTWD)

Making A Weld

1.See “Process Guidelines” in this section for selec- tion of welding wire and shielding gas and for range of metal thicknesses that can be welded.

2.See the Application chart on the inside of the wire feed compartment door for information on setting the PRO 100 controls. Refer to Table B.1 for alu- minum and stainless wire.

3.Set the Voltage (“V”) and Wire Speed (“olo’”) con- trols to the settings suggested for the welding wire and base metal thickness being used, refer to Applications chart on the inside of the wire drive compartment door.

4.Check that the polarity is correct for the welding wire being used and that the gas supply, if required, is turned on.

5.When using Innershield electrode, remove the gas nozzle and install the gasless nozzle. This will improve visibility of the arc and protect the gas dif- fuser from weld spatter. Refer to the MAINTE- NANCE section for details on nozzle replacement.

FIGURE B.7

GUN CABLE

WORKPIECE

ARC

WORK CLAMP

6.Refer to Figure B.7. Connect work clamp to metal to be welded. Work clamp must make good elec- trical contact to the workpiece. The workpiece must also be grounded as stated in “Arc Welding Safety Precautions” in the beginning of this manu- al.

7.Position gun over joint. End of wire may be lightly touching the work.

8.Lower welding helmet, close gun trigger, and begin welding. Hold the gun so the contact tip to work distance is about 3/8 inch (10 mm).

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 PRO 100.

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 PRO 100 as shipped, can be used for welding mild steel using the self shielded, Innershield elec- trode process or it can be used for the GMAW (MIG), single pass, process which requires a supply of shielding gas and the K610-1 MIG Conversion Kit.

The recommended electrode for the self-shielded process is 0.035” (0,9 mm) diameter Lincoln Inner- shield NR-211-MP. Requires optional spindle – refer to Accessories section. 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 recommended gas and electrode for GMAW is welding grade CO2 gas and 0.025” (0 6 mm) diameter Lincoln Super Arc L-56 mild-steel welding wire [sup- plied on 12-1/2 Ib (6 kg) spools]. For 14 gauge (2,0

mm)and thinner, CO2 gas is recommended because it gives equal or better performance than a blended gas at a lower cost. A mixed gas consisting of 75 to

80% Argon and 20 to 25% CO2 is recommended for welding on heavier gauge steel, 12 gauge (2,5 mm) for example.

PRO 100