the rear of the guide tube. Hold the guide tube perpendicular to a steel
plate or other hard, flat object and strike the end of the wire on the
plate. If this does not free the wire, cut off the melted section of the
guide tube, to free the wire. Remove the burr and put the tube back into
the gun, maintaining the proper distance from the nozzle to the end of the
guide tube. A tube may be trimmed about 3/8 of an inch before it becomes
too short and must be discarded.
The gas holes in the gun barrel may become clogged with a white residue,
which will eventually obstruct the gas flow. It is a good idea to dismantle
the gun every 100 hours and blow out these gas holes with a high pressure
Care should be taken to see that the front nylon guide bushing (3) does
not become damaged to the extent that the shielding gas is wasted by ex-
cessive leakage back into the drive roll cavity of the main casting.
The control monitor, under normal operating conditions, needs no maintenance.
The control door can be opened by twisting the screw latch.
Regulator and Flowmeter - Inspect for leaks and improper operation.
Welding Gun - Inspect for leaks and improper operation. Clean spatter
from nozzle. Replace nozzle if damaged in such a way that gas flow
from nozzle is changed. Inspect guide tube for damage such as burrs
or melted weld metal adhering to end. Replace guide tube if beyond re-
Inspect front nylon bushing for excessive wear and replace if
Argon Gas Regulator - Inspect for cracks, leaks, and improper operation.
Hose and Cable Assemblies - Inspect for worn, frayed, and other damaged
conditions. Inspect for loose connections on the hose and electrical
Contactor - Inspect for defective wiring.
Test the contactor for im-
Solenoid Valve - Inspect for leaks and loose electrical connections.
Test for improper operation.