Welders can execute a 3F weld in two directions, depending on the project requirements:
| Defect | Cause | Prevention | |--------|-------|-------------| | Undercut (on vertical plate) | Excessive heat, poor edge pause | Pause slightly at top edge of weave | | Sagging / convex bead | Too slow travel speed | Increase speed, reduce heat input | | Lack of fusion (corner) | Arc not directed into root | Aim arc into the 45° corner | | Slag inclusion (FCAW/SMAW) | Improper cleaning between passes | Chip/grind thoroughly after each pass | | Excessive spatter | Long arc length or wrong parameters | Keep short arc, adjust voltage/amperage | 3f welding position