Lincoln Electric IM666-A manual Operation, Electrodes and Equipment, Making a Weld

B-1 OPERATION B-1

ELECTRODES AND EQUIPMENT

TheTandem MIG torch has been designed for use with 0.035" through 5/64" (0.9 mm to 1.9 mm) Lincoln solid steel MIG wires and metal core wires. Refer to the appropriate Lincoln Process and Procedure Guidelines for further information on welding settings.

MAKING A WELD

WARNING

• When using an open arc process, it is necessary to use correct eye, head and body protection.

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a)Check to make sure the welding power sources are turned on and set to the correct parameters and programs.

b)Verify that the shielding gas supply is on and set for the correct flow rate.

c)Set the preflow and postflow times the same on both wire feeders. Make sure the post flow is long enough to provide shielding during any crater fill operation.

d)Check that all of the water coolers are operating properly.

e)If applicable, make sure the Air-Blast spray sys- tem is on.

f)Position the torch over the joint.

WARNING

•Automatic equipment may start unexpectedly.

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g) Make a weld by sending a trigger signal to the welding power sources.

AVOIDING WIRE FEEDING

PROBLEMS

Wire feeding problems can be avoided by observing the following procedures:

a)Do not use a torch with cables longer than neces- sary.

b)Do not kink or pull the cable around sharp corners.

c)Keep the cable as straight as possible when welding or loading electrode through the cable.

d)Do not allow dolly wheels or trucks to run over cables.

e)Use only clean, rust-free electrodes. Electrodes manufactured by Lincoln Electric have proper surface lubrication.

f)Replace the contact tips when the arcs start to become unstable or the contact tip ends are fused or deformed.

SHIELDING GAS DELIVERY

Adjust flow regulators for prescribed gas flow. Inspect hoses regularly for worn or torn hoses. Perform a soapy water test on hoses if a leak is suspected. Avoid kinking or collapsing hoses with cable clamps. Insure that dif- fuser is properly seated and tight. For G3494-XA series torch, two gas sources are required. Do not attempt to “Y” or Tee gas from one flow meter or regulator.

AIR BLAST CLEANING

The welding torch is equipped with a separate gas hose for the purpose of providing a high pressure air blast through the nozzle area to clear loose spatter that may have accumulated between the two diffusers.

The high-pressure air is routed through the torch over molded assembly and exits into the nozzle through an opening in the nozzle shield. Air should be dry and free of oil or anti- spatter compound. Pressure should be ade- quate to free loose spatter (50-100 psi).

NOZZLE REAMING STATIONS

During robotic applications a reamer should be employed to keep the nozzle clean. Reaming the nozzle between welds will reduce the down time associated with manual torch cleaning. The M18426-1 reaming station is an option that is recommended for nozzle cleaning.

ANTI- SPATTER SPRAY

Anti-spatter compound may be used to keep weld spatter from accumulating in the nozzle. Anti-spatter should not be applied through the air blast line. Only dry air should be used for air blast functions.

Anti-spatter may be applied to the interior of the nozzle from an external sprayer. The M18426-1 reaming station comes equipped with an external anti-spatter spraying station.

Care should be taken to apply the right amount of anti- spatter to the internal area of the nozzle. Too much anti - spatter will cause diffuser clogging and weld porosity.

Only a very light covering of anti-spatter is required to keep the spatter from cling to the nozzle.

TANDEM MIG TORCH