Chapter 16 GMAW and FCAW Equipment Assembly and

Chapter 16 GMAW and FCAW: Equipment Assembly and Adjustment Miller Electric Mfg. Co.

Learning Objectives • Assemble a GMAW/FCAW welding outfit. • Adjust the drive mechanism for the proper pressure and alignment. • List the proper sequence for removing a bird’s nest. • Adjust the shielding gas flowmeter for the proper pressure and flow rate. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Learning Objectives (Cont. ) • Identify the electrode wire designations for GMAW electrodes. • Identify the electrode wire designations for FCAW electrodes. • Identify the two adjustments that are made to the welding machine. • Identify safety precautions for GMAW and FCAW. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Introduction • Proper setup and assembly are critical • Connections must be made and adjusted correctly Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Gas Cylinder Safety • Take care when handling or moving cylinders • Secure cylinders to wall, column, or hand truck at all times • Protect cylinder valve with safety cap • Do not point cylinder valve at any workers while cleaning Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Cylinder, Regulator, and Flowmeter Setup • Clean cylinder – Quickly open and close cylinder valve – Do not point cylinder valve at any workers while cleaning • Attach regulator • Install flowmeter CONCOA Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Setup • Connect hose from flowmeter to welding machine or wire feeder • Separate wire feeder – Connect to remote contactor control – Connect to power source • Connect welding gun to wire feeder – Combination hose – Additional shielding hose Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Setup (Cont. ) Miller Electric Mfg. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Wire Feeder Setup • Selectrode wire • Mount electrode wire on wire spool hub • Install proper drive rolls – V-groove – Knurled rolls Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Loading Electrode Wire • Move pressure rolls • Push wire through inlet wire guide • Feed into drive roll grooves and outlet wire guide • Replace pressure rolls The Lincoln Electric Co. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Aligning the Pressure Rolls Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Bird’s Nest • Improper feeding • Blockage in cable • Misaligned guide tubes and rolls • Burning electrode wire back to contact tube • Stubbing electrode wire Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Removing a Bird’s Nest • Cut and remove tangled wire • Remove electrode wire from cable connected to gun • Refeed electrode wire through guide tubes and to welding gun Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Gun Setup • • Check contact tube and replace if necessary Attach nozzle Remove spatter on contact tube and nozzle Use welpers to remove or install contact tubes and nozzles Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Adjusting the Shielding Gas Flowmeter • Attach regulator and flowmeter • Open cylinder valve • Start gas flow – Purge switch – Post-flow adjustment • Turn adjusting screw to correct rate • Reset post-flow time Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Factors for Selecting Electrode Wire • • • Base metal composition Base metal properties Cleanliness of base metal Shielding gas Metal transfer method Welding position Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

GMAW Electrodes Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

AWS Designations for GMAW Electrodes Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

FCAW Electrodes Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

AWS Designations for FCAW Electrodes Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Variables for FCAW Electrodes Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Dash Number • Numerals or letters following dash in electrode designation • Information provided – Polarity to use – Shielding gas to use (if required) – Whether electrode can be used for multiple-pass welds Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Electrode Wire Diameter • Selected after electrode is chosen • GMAW and cored electrode diameters –. 030″ to 1/16″ –. 8 mm to 1. 6 mm • FCAW electrodes –. 045″ to 1/16″ – 1. 2 mm to 1. 6 mm Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Settings • Two settings must be adjusted – Voltage – Wire feed speed • Adjusting these two variables determines arc length and current Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Settings for Mild and Low-Alloy Steel Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Settings for Series 300 Stainless Steel Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Settings for Aluminum and Aluminum Alloys Goodheart-Willcox Publisher Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Settings for FCAW-G Mild and Low-Alloy Steel Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Welding Machine Settings for FCAW-S Mild and Low-Alloy Steel Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Preparing the Base Metal • Clean to remove oxides, oil, and debris – Chemical cleaning – Mechanical cleaning • Prepare joint edges if necessary Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Microprocessor Welding Machines • Base metal type, electrode diameter, and shielding gas are entered into machine • Based on information input, machine has set of predetermined voltages for any set wire feed speed • Preset values can be adjusted and saved as a set of parameters Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Safety Precautions • • Wear proper clothing and eye protection Check that equipment is assembled correctly Check that equipment is operating properly Check that there is adequate ventilation Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Shutting Down a GMAW/FCAW Station • To avoid damage, follow these steps in order: 1. 2. 3. 4. 5. 6. 7. Adjust flowmeter to stop shielding gas flow Close cylinder valve on manifold Readjust flowmeter to restart shielding gas flow Press purge switch on wire feeder Turn wire feeder off Turn welding machine off Coil cables and store properly Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.