The primary enemy in 2G welding is gravity pulling the molten puddle downward. Because the base metal is vertical, the molten filler metal naturally wants to roll down the face of the plate, creating undercut at the top toe of the weld and overlap (cold roll) at the bottom.
In 2G, hesitation is fatal. If you pause too long, the puddle builds up and rolls over. If you move too fast, you trap slag or lack fusion. The sweet spot is a steady, rhythmic movement that stays ahead of the molten pool but doesn't outrun the shielding gas.
| Criteria | Requirement | |----------|--------------| | Reinforcement | 0" – 1/8" (0–3.2 mm) | | Undercut | Max depth 1/32" (0.8 mm), not exceeding 1" length in 12" | | Porosity | None visible (for radiographic/visual inspection) | | Cracks | Not allowed | | Incomplete fusion | Not allowed | | Penetration (root) | Full fusion without excessive drop-through | welding 2g position
The 2G horizontal position is a fundamental welding qualification test that demands good puddle control and proper technique to counteract gravity. Mastery of 2G is essential for structural and pipe welders, as it bridges the gap between basic flat welding and more advanced positions like vertical (3G) and overhead (4G).
Vertical for plates; fixed vertically for pipes (+/- 15º). The primary enemy in 2G welding is gravity
Why do certification tests heavily feature 2G?
To the uninitiated, 2G looks simple. The plate is vertical, but the weld is horizontal. Yet, anyone who has ever picked up a stinger knows that 2G is the ultimate test of your ability to control the weld pool when gravity is trying to pull it out of the joint sideways. If you pause too long, the puddle builds up and rolls over
The 2G welding position! Let's review what it's all about.