This is a common point of confusion. According to AWS A3.0:
According to AWS A3.0 :
Success in the 4F position relies heavily on proper joint preparation, torch angles, and travel speed. Here is the standard procedure for shielded metal arc welding (SMAW/Stick) and gas metal arc welding (GMAW/MIG) in the 4F position. 1. Safety and Setup
Use a foot pedal or torch amperage control to constantly back off the heat as the base metal saturates. 4f welding position full
The intersection forms a "T" or a "Lap" joint where the weld metal is deposited into the corner from below. 2. Analyze Gravitational Challenges
| Defect | Primary Cause in 4F | Solution | | :--- | :--- | :--- | | | Too much heat; puddle sagging away from vertical wall. | Reduce amperage; tighten arc length; pause slightly at the vertical wall. | | Convexity (bulging weld) | Travel speed too slow; excessive deposition. | Increase travel speed; use a smaller electrode/wire. | | Slag Inclusion | Slag running ahead of arc; improper cleaning between passes. | Increase drag angle; chip/grind thoroughly between passes. | | Overlap (cold lap) | Amperage too low; travel angle too steep. | Increase heat slightly; reduce drag angle to 5°. | | Burn-through (on thin material) | Excessive heat input; moving too slow. | Use smaller electrode; faster travel; backstep technique. |
: Use full-body protection, including a leather jacket and a bandana under your helmet, as sparks and spatter will fall directly toward you. 2. Set Parameters This is a common point of confusion
Wait – I must correct my own text. The position is OVERHEAD fillet , not vertical fillet. Vertical fillet is 3F.
Provide tips on troubleshooting common 4F defects like sagging or undercut Let me know what you'd like to dive into next! Share public link
Defying Gravity: The Art and Grit of the 4F Welding Position not vertical fillet.
Top View (from above the joint): | (Vertical plate) | |_______ (Horizontal plate – underside is where weld is made)
Flux-cored wire is highly effective for heavy industrial overhead applications due to its fast deposition rates.
A successful 4F weld should look just like a flat fillet weld turned upside down. Inspect your finished weld for the following criteria: