Slide 002: TIG Welding Technique — Torch Control & Filler Rod Addition

Slide Visual

Slide Overview

This slide covers the core TIG welding technique — simultaneously controlling the torch position, arc length, filler rod addition, and foot pedal amperage. TIG requires coordination of both hands and one foot, making it the most skill-intensive welding process.

Instruction Notes

The Three-Limb Coordination Challenge

TIG welding requires simultaneous control of: 1. Dominant hand: Torch — controls arc position, angle, and travel speed 2. Non-dominant hand: Filler rod — controls filler addition timing and amount 3. Foot: Pedal — controls amperage in real-time

This three-way coordination is the primary challenge. Each limb operates independently but must be synchronized with the others.

Torch Hold & Position

• Hold the torch like a large pencil — fingers wrap around the body, thumb supports
• Rest your forearm or wrist on the table for stability
• Torch angle: 15°–20° from perpendicular, tilted BACK (trailing the direction of travel)
• Arc length: maintain approximately 1 electrode diameter (e.g., 3/32" for a 3/32" tungsten)
• Travel: push the torch forward at a steady pace, moving the weld pool along the joint

Establishing the Weld Pool

1. Position the torch at the start of the joint
2. Press the foot pedal gradually — watch for the base metal to begin melting
3. A shiny, circular puddle should form (approximately 2× electrode diameter)
4. Maintain the pool for 1-2 seconds before adding filler or beginning travel
5. The pool surface should be mirror-smooth — ripples indicate turbulence or contamination

Filler Rod Technique (Dip & Withdraw)

The defining rhythm of TIG welding:

1. Advance the torch slightly (one pool-width forward)
2. Dip the filler rod into the leading edge of the pool at a 15°-20° angle to the workpiece
3. The rod melts into the pool — a small amount of filler is added
4. Withdraw the rod from the pool (but keep it within the gas shield, 1" from the arc)
5. Advance the torch again
6. Repeat: advance → dip → withdraw → advance → dip → withdraw

This creates the characteristic "stacked dimes" or "walking the cup" appearance.

Common mistakes: - Holding the rod in the arc continuously → rod balls up, spatter, tungsten contamination - Dipping too much rod → weld bead too tall, cold lap risk - Dipping too little → concave bead, potential undercut - Rod too far from the pool → rod oxidizes (turns black), contaminates the next dip

Foot Pedal Control

• Start: Ramp up gradually (over 1-2 seconds) — avoid blasting full amps on cold metal
• Welding: Maintain steady pressure — adjust if the pool gets too large (ease off) or too small (press more)
• Corners and tack welds: Reduce amps to prevent burn-through at points that accumulate heat
• End (crater fill): Gradually reduce amps over 2-3 seconds while adding a final dip of filler — this prevents a shrinkage crack in the crater
• Never release the pedal abruptly — the sudden arc stop creates a depression (crater) that is prone to cracking

Travel Speed

TIG is SLOW compared to MIG: - Typical travel speed: 3-6 inches per minute (vs. 10-20 IPM for MIG) - Watch the weld pool — it should maintain a consistent size - If the pool grows: speed up or reduce amps - If the pool shrinks: slow down or increase amps

Key Talking Points

1. TIG is a three-limb coordination skill — it takes dedicated practice to develop
2. The dip-and-withdraw rhythm creates the stacked-dime appearance
3. The foot pedal is your real-time heat control — master it and you master TIG
4. Crater fill (ramping down at the end) prevents cracking — never release the pedal abruptly
5. Patience is the #1 virtue — TIG is slow, precise, and meditative

Learning Objectives (Concept Check)

• [ ] Demonstrate proper torch hold, angle, and arc length control
• [ ] Perform the dip-and-withdraw filler rod technique with consistent rhythm
• [ ] Control amperage via foot pedal including proper start-up and crater fill

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Last Updated: 2026-03-19