Overhead welding: how to run it so the pool does not drip
Overhead is the most awkward position of all: the molten metal is held up by surface tension alone, and everything surplus falls on the welder. The whole technique comes down to one thing — keep the pool small.
When you have to weld overhead
When the part cannot be turned: pipework fitted in place, beams and columns in a structure, repairs under a machine. In a workshop it is almost always cheaper to roll the job over than to weld above your head — on site there is no such choice.
How to run it
Take the current 10–15 % below the flat position and a thinner electrode, usually 2.5 or 3.2 mm. The arc must be very short: a long arc means a dripping pool. Run narrow beads, straight or with a small weave, and never dwell in the middle. Hold the electrode nearly square to the plate with a slight drag angle.
Guide settings for a basic electrode
| Thickness, mm | Electrode diameter, mm | Current, A |
|---|---|---|
| 2,0 | 2,5 | 60–80 |
| 3,0 | 2,5–3,2 | 80–110 |
| 4,0 | 3,2 | 100–130 |
| 6,0 | 3,2–4,0 | 120–160 |
| 8,0 | 4,0 | 140–180 |
What to weld with
Basic electrodes hold overhead best: their slag freezes quickly and props the pool up. Rutile ones run and drip. In MIG/MAG, overhead is run in short arc or pulse, with a short stickout and an argon-rich mix — pure CO₂ throws droplets that are far too big.
Safety in the overhead position
Sparks and droplets fall straight onto the welder, so the jacket is buttoned to the throat, sleeves go over the gauntlets and trouser legs over the boots. Add a neck cape to the helmet. This is the one position where spatter finds its way into a collar and a sleeve — that is where the burns come from.
Typical defects
Excess reinforcement and overlap — the pool was too big. Porosity — the shielding was blown away or the electrode was damp; overhead it shows immediately. Lack of root penetration, when the welder drops the current too far for fear of dripping.
Designation and qualification
Overhead is PE to EN ISO 6947 (overhead fillet is PD), 4G and 4F in the American system. A qualification passed in PE covers the easier positions, which is why an overhead test counts for more than a flat one.
Frequently asked questions
What current for overhead welding?
Ten to fifteen per cent below the flat position at the same thickness. For a 3.2 mm electrode that usually lands between 100 and 130 A. Too little current is just as harmful: you get lack of root penetration.
Which electrodes are used overhead?
Basic ones work best: their slag freezes quickly and props the pool up. Rutile electrodes run and drip, so overhead they are limited to thin sizes on thin material.
Does an overhead qualification cover other positions?
Largely yes: PE is a difficult position and under EN ISO 9606-1 it covers the easier ones. The exact range is worked out from the test details, because it also depends on the joint type and the thickness.
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