Hand Coordination: Filler Rod Feeding Techniques and Puddle Timing

Why Hand Coordination Matters in TIG

TIG welding is a two-hand process: one hand controls heat placement with the torch, and the other controls metal addition with the filler rod. Clean, consistent beads come from a repeatable rhythm where the puddle is formed, filler is added at the correct spot and time, and the torch advances the same distance each cycle. When timing is off, you’ll see common symptoms: uneven ripple spacing, a bead that alternates between tall and flat, underfilled toes, or occasional porosity from a filler tip that leaves the shielding gas envelope.

The Core Rhythm: Puddle → Add → Advance → Repeat

Think of TIG travel as a metronome. Each “beat” is one controlled addition of filler and one controlled movement forward. Your goal is to make each cycle identical.

1. Establish the puddle: Hold the torch steady long enough for a small, stable molten pool to form. The puddle should be just large enough to accept filler without collapsing or spreading uncontrollably.

2. Add filler at the leading edge: Touch the filler to the front of the puddle (the edge closest to where you’re going next). This places metal where the joint needs it and helps the puddle “pull” forward.

3. Let it melt, then withdraw slightly: The filler should melt smoothly into the puddle. Withdraw the rod just enough to break contact and avoid sticking, but keep the tip protected (more on this below).

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4. Advance the torch: Move the torch forward a small, consistent distance—often roughly the width of one ripple—then pause briefly to re-establish the puddle shape.

5. Repeat with the same timing: Consistency in pause time, filler amount, and step length creates consistent ripple spacing and bead profile.

Puddle Timing: What You’re Watching

Instead of thinking “add filler whenever,” watch for a repeatable visual cue: the puddle reaches a stable size and shine, then you add filler. If you add too early, the rod chills the puddle and you get a lumpy bead. If you add too late, the puddle grows and flattens, risking undercut at the toes or excessive width.

• Correct timing: puddle is stable, edges are defined, filler melts in quickly, bead stays uniform.
• Too fast: filler piles up, ripples crowd together, bead looks ropey.
• Too slow: bead gets wide/flat, ripples stretch apart, toes may wash out.

Keeping the Filler Tip Inside the Shielding Gas Envelope

Porosity and “peppery” contamination often come from the filler tip oxidizing between dips. The fix is simple in concept and requires discipline in practice: keep the hot end of the filler rod inside the shielding gas envelope whenever possible.

Practical Rules That Prevent Oxidized Filler Dips

• Short withdrawals: after each dip, pull the rod back only a small distance—just enough to clear the puddle—rather than yanking it far away.
• Approach from the side: feed the rod in from a low angle so the tip stays near the gas coverage while you reposition.
• Don’t “park” the rod outside: if you pause, pause with the tip still protected rather than hovering in open air.
• Re-entry should be smooth: stabbing back into the puddle tends to flick the tip out of coverage and can introduce oxides.

A helpful mental model: the filler tip should live in a “protected bubble.” You can move it within that bubble between additions, but avoid leaving it and coming back with a hot, oxidized tip.

Filler Feeding Methods: When to Use Each

Different joints, positions, and bead lengths favor different ways of feeding filler. The best method is the one that lets you maintain the puddle rhythm without losing control of the filler tip position.

1) Dip Feeding (Touch-and-Withdraw)

What it is: You advance the rod, touch the leading edge of the puddle to deposit a small amount, then withdraw slightly and repeat.

Best for:

• Most beginner practice beads on plate
• Fillets and butt joints where you want clear control of each addition
• Situations where you need to vary filler amount frequently (start/stop, fit-up changes)

Key coordination points:

• Dip at the leading edge, not the center of the puddle.
• Withdraw only enough to prevent sticking; keep the tip protected.
• Match dip frequency to travel speed so ripple spacing stays consistent.

2) Incremental Finger-Feed (Walking the Rod Forward)

What it is: The filler hand “ratchets” the rod forward in small increments using finger and thumb movements while the rod remains generally pointed at the puddle. You still dip, but you don’t have to reposition your whole hand as often.

Best for:

• Longer beads where you want steady, repeatable filler delivery
• Bench work where your filler hand can be braced for stability
• When consistent ripple spacing is the priority

Key coordination points:

• Separate the actions: feed forward during the advance/pause, dip on the beat.
• Keep the rod angle consistent so the dip location doesn’t wander.
• Use a light grip; tension makes the rod jump and disrupts timing.

3) Lay-Wire (Supported Filler) for Certain Cases

What it is: The filler is laid along the joint line and melted progressively as you move forward, rather than being dipped in discrete touches. This is not a universal technique; it’s a situational tool.

Appropriate for:

• Some thin material or edge joints where tiny, continuous additions help prevent overheating
• When access makes dipping awkward and you can keep the wire stable and clean
• Short, controlled runs where you can maintain consistent contact and avoid pushing oxides into the puddle

Use caution:

• Lay-wire can encourage dragging contaminants if the wire is not kept clean and stable.
• It can also tempt you to outrun the puddle; keep the same puddle → melt → advance rhythm, just with a more continuous filler presence.

Step-by-Step: Building a Repeatable Rhythm

Step 1: Set Your Bracing and Range of Motion

Before striking an arc, decide how both hands will move. The torch hand should have a stable pivot (wrist/forearm braced), and the filler hand should have a comfortable feed path that doesn’t require large, jerky movements.

• Torch hand: plan a smooth forward slide or pivot; avoid lifting and re-planting every inch.
• Filler hand: plan how you will feed (dip-only repositioning vs finger-feed increments).

Step 2: Run the “Four-Count” in Your Head

Use a simple count to lock in timing. Example:

1 = establish puddle (brief pause) 2 = dip at leading edge 3 = withdraw slightly (stay protected) 4 = advance torch (small step)

Repeat the same count for the entire bead. If the bead starts to look uneven, don’t immediately change settings—first check whether your count sped up or slowed down.

Step 3: Control Filler Amount Like a Measured Dose

Each dip should add a similar amount of metal. If you need more buildup, increase the amount per dip or dip frequency—but change only one variable at a time so you can see cause and effect.

Skill-Building Drills (Progressive)

Drill 1: Dry-Run Without Arc (Coordination Only)

Goal: build the motion pattern without heat, glare, or noise.

1. Set up your workpiece and assume your welding posture with both hands braced.

2. Hold the torch in position above the joint line (no arc) and place the filler rod at your intended approach angle.

3. Practice the rhythm: pause (puddle moment), dip motion to the leading edge (simulate a touch), withdraw slightly, advance torch a small step.

4. Do 20–30 “beats” in a row without changing your bracing points.

Checks: Is your torch step length consistent? Does the filler tip return to the same spot every time? Are you withdrawing only a small distance?

Drill 2: Short Beads with Controlled Filler Addition

Goal: connect visual puddle cues to your dip timing.

1. Run a short bead length (for example, a few inches) focusing on a strict count.

2. Make each dip identical: same depth of touch, same withdrawal distance, same pause time.

3. Stop and inspect: ripple spacing and bead width should be uniform across the short run.

Variation: Repeat the same short bead while changing only one variable: either dip frequency or torch step length. Observe how the bead changes.

Drill 3: Longer Beads Focused on Consistent Ripple Spacing

Goal: maintain rhythm over time without drifting technique.

1. Choose a filler feeding method (dip or finger-feed) that you can sustain comfortably.

2. Commit to a steady “beat” and keep your torch step length consistent.

3. As you progress, periodically check yourself mid-bead: is the filler tip still staying protected between dips? Are you reaching and changing angles, or are you moving your body/brace to keep geometry consistent?

Self-audit during the run: If ripple spacing starts to widen, you likely sped up travel or reduced pause time. If ripples crowd, you likely slowed travel or increased dip frequency. Correct rhythm first, then reassess.