Fundamentals of Gas Metal Arc Welding (GMAW/MIG)

Explore the fundamentals of gas metal arc welding (GMAW/MIG), including transfer modes, shielding gas, equipment, filler metals, pre- and post-welding procedures, and FCA as a subdivision.

Operate gas metal arc welding by feeding a continuous wire electrode with a shielding gas to protect the weld pool, enabling semi-automatic welding for ferrous and nonferrous metals.

Learn how GMAW (MIG) welding uses shielding gas, electrical current, and wire feed to deposit weld metal, with argon/CO2 shielding, adjustable heat input, and streamlined, less-skill-intensive deposition without slag.

Explore the principles of gas metal arc welding (GMAW/MIG), including wire feed, current, and shielding gas, and how shielding protects the weld puddle from oxygen and nitrogen.

Learn how GMAW/MIG uses wire feed speed to control current and voltage, and explore four transfer modes—short circuiting, globular, spray, and pulse spray—and their ideal applications.

Describe pulse spray and short-circuiting GMAW techniques, root passes, uphill and out-of-position welding, and how current, voltage, wire feed, shielding gas, and travel speed govern penetration and deposition.

Explore gas metal arc welding transfer modes: short circuiting, globular, spray, and pulse spray, and how wire size, shielding gas, current, and voltage shape these processes.

Identify gas metal arc welding transfer modes, including short circuiting, globular, spray, and pulse spray transfer, by voltage range, shielding gas, and current.

Learn gas metal arc welding (GMAW/MIG) equipment, including power supplies, wire feeders, the welding gun, and the shielding gas system, to deposit weld metal while shielding the weld puddle.

Identify GMAW/MIG gun components—from trigger and liner to gas diffuser, contact tube, nozzle, and wire—and summarize how power sources, duty cycles, and shielding gas affect welding.

Learn GMAW equipment basics, including drive and feed rolls, wire path to the gun liner, and shielding gas selection with flow meters to protect the weld puddle.

Explore gas metal arc welding gun and wire feed troubleshooting, covering feed rolls, gun liner, contact tips, diffusers, nozzles, and shielding gas to prevent birds nesting and ensure clean welds.

Discover how shielding gases in gas metal arc welding protect the weld from oxygen and nitrogen, control arc stability and transfer mode, and influence penetration and bead profile.

Learn how carbon dioxide and argon-co2 mixes influence weld penetration, bead shape, and transfer modes in gmaw/mig, and how helium and argon-oxygen blends affect arc stability, spatter, and heat dissipation.

Understand gas metal arc welding filler classifications, from solid to metal core and flux core wires, and how ASME section II C and AWS standards govern chemistry and performance.

Master pre weld preparation for GMAW/MIG by cleaning joints, ensuring proper fit-up, and applying preheating when needed; use fixturing to control alignment, distortion, and heat buildup for efficient welding.

Preheating decisions depend on metal type, base material, thickness, joint restraint, and code, with various heating methods and inner pass temperature controls to protect weld microstructure.

Learn post-welding procedures for gas metal arc welding, including cleaning with wire brushes and post-weld heat treatment. Identify nondestructive testing and repair methods like grinding or gouging to meet codes.

Compare flux cored arc welding with gas metal arc welding, noting flux inside the wire and shielding. Flux cored arc welding offers high deposition rates, with self-shielded and gas-shielded methods.

Learn flux core arc welding, including self shielded and gas shielded variants, with fluxed wire and slag removal, and assess high deposition rates, outdoor use, fumes, and cost tradeoffs.

Explore flux cored arc welding electrodes, including self shielded and gas shielded forms, and contrast them with gas metal arc welding solid wires, noting ASME and AWS standards.

Conclude your learning by revisiting core terminology and concepts of gas metal arc welding, and leverage lifetime access to updates, with questions welcome on YouTube or the instructor page.

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