Push or Drag
Travel angle aims the arc's heat and force at the puddle or at bare plate: drag digs deep and narrow, push spreads wide and shallow. · 12 min
The machine is set; now every result comes from your hand. Three things your hand controls: stickout — the bare wire between contact tip and work; work angle — the gun's tilt across the joint; and travel angle — its lean along the direction of travel. Stickout has one right answer for now: about 3/8 inch. Travel angle has two schools, push and drag, and choosing between them is this folio's work.
Guess before you learn
Tilt the gun so the wire points ahead, in the direction you are traveling — the push technique. Compared with dragging, what happens to penetration, the depth the weld melts into the plate?
Shallower. Pushing aims the arc ahead of the puddle onto cold plate, and the melt spreads wide and thin. If you guessed deeper, you are in good company — pointing forward feels aggressive. The section ahead shows where the heat actually lands.
9–12
3–5
The arc is a small, fierce jet of heat coming off the wire. Leaning the gun aims that jet. Aim it back into the melted pool and it drills downward, making a deep, narrow weld. Aim it forward onto cold metal and the pool spreads out wide and shallow.
6–8
Two named angles. Work angle is measured across the joint — near 90 degrees for a flat bead on plate. Travel angle is measured along the direction of travel, and it stays modest either way: 5 to 15 degrees of lean. The choice is which way to lean.
Drag — also called pull or backhand: the gun trails, wire pointing back at the puddle. The arc bores down beneath the puddle for deeper penetration and a narrower, more built-up bead. Push — forehand: the gun leads, wire pointing ahead. The arc preheats bare plate and the puddle follows over it: wider, flatter, shallower, with a better view of the joint.
9–12
The mechanism is where energy lands. Dragging directs arc force into metal already molten; the pressure depresses the puddle, thinning the liquid cushion under the arc so heat conducts straight down into the plate. Pushing directs force ahead of the puddle; energy spreads across solid, colder metal and the puddle rides shallow behind it.
Stickout matters for the same accounting. The bare wire past the contact tip is a resistor carrying full welding current, and it preheats. Stretch the stickout and the machine — holding voltage — cuts current back; penetration falls. Hold it near 3/8 inch and your settings mean what the chart said.
K–2
The welding torch can lean two ways while it moves. Lean it back, toward the finished line, and the melt digs deep and narrow.
Lean it forward, the way you are going, and the melt spreads wide and shallow. Same torch, same heat — the lean chooses the shape.
Undergrad
Arc pressure scales roughly with the square of current and acts along the electrode axis, so the travel-angle decision is a vector decision: the axial momentum flux impinges either on the melt (drag, deepening the pool depression) or on unfused base metal (push, distributing the same power over a larger, colder footprint).
Electrode extension adds a Joule-heating term: at fixed wire-feed speed, a longer extension needs less arc current to sustain burn-off, so the constant-voltage machine sheds amps. Penetration is a current phenomenon before it is a technique phenomenon — the extension quietly rewrites the current.
Postgrad
Puddle behavior under a moving arc is a coupled free-surface problem: arc pressure depresses the pool, Marangoni flows redistribute superheat, and travel angle sets whether the stagnation region of the plasma jet sits over liquid or solid. Drag configurations deepen the depression and steepen the thermal gradient into the substrate.
Process comparison belongs in the same quantitative register: GMAW's deposition efficiency and duty cycle beat SMAW's on clean, fixtured work, while SMAW's flux system buys tolerance of surface condition and ambient air. Selection is constrained optimization, not ranking — the constraint set of wind, fit-up, position, and access picks the process.
stickout
The bare wire between the contact tip and the work. Hold it near 3/8 inch; a stretched stickout bleeds current and penetration.
Now the honest comparison you have earned. MIG is faster: no rod changes, no slag to chip between passes, and an arc that regulates itself. On clean shop steel it is the easy process to run and the easy process to learn. But its shielding is a loose envelope of gas — a 5-mile-per-hour breeze strips it away — and bare wire has no flux to burn through rust, paint, or mill scale.
Choose the hold for a 3/16-inch tee joint — the steps fade as you master them
3/8 inch of wire past the tip
Drag: wire pointing back at the puddle
5–15 degrees of travel angle — call it 10
Narrow, slightly crowned, deep at the root
Push or drag is a decision you will make on every weld from now on, and it never becomes automatic — it stays a choice, keyed to the metal's thickness and the bead you owe the joint. Next folio: the finished bead itself, read as evidence.
Practice — new ink and old, interleaved
1.Re-striking mid-bead with a half-used rod: where does the new arc start?
2.Your MIG bead is tall, ropey, and barely tied into the plate. Order the checks.
- Check stickout is near 3/8 inch, not stretched
- Confirm voltage and wire speed against the chart
- Switch to a slight drag with 5–15 degrees of lean
- Run a test bead on scrap and read it
3.A bead came out wide, flat, and shallow. Which hold produced it?
4.A sound travel angle, in degrees of lean from vertical.
5.Your arc keeps snapping out a few seconds after each strike. Most likely cause?
6.When is the tap start the better choice?
7.Name one job where stick beats MIG and one where MIG beats stick, with the reason.
Stick wins outdoors on rusty steel because flux shielding survives wind and dirty metal; MIG wins on clean shop steel because continuous wire is faster with no slag to chip.
How close were you? Grade yourself honestly — it sets your review date.