vertical, and overhead, Figure 6-21. The effect of gravi-
ty on the molten weld pool differs with each position.
Heat distribution also varies. These two factors make the
skills for each position distinct. Practice is necessary to
produce good welds in all positions. There are several
considerations when welding in the various positions:
• The flat position has the greatest deposition rate.
Flat welds usually have less porosity because the
gas can rise to the top of the weld pool and escape
before the metal solidifies.
• Undercut at the top of the weld pool can be a
major problem in the horizontal position.
• Heat rises during vertical welding, requiring
close observation of the molten pool to prevent
sagging and overheating of the weld.
• Overhead welding is the most tiring of all posi-
tions. It also has the slowest metal deposition.
Making wash beads is extremely difficult due to
metal sagging. Overhead welds are prone to
porosity.
54 Flux Cored Arc Welding Handbook
Figure 6-21. Positions for fillet welds, grooved butt welds, and pipe welds.
Grooved Butt Welds Pipe Welds
Flat 1G
Horizontal 2G
Vertical 3G
Rotated flat rolled 1G
Horizontal 2G
Vertical fixed 5G
Fixed 6G
Overhead 4G
Fillet Welds
Flat 1F
Horizontal 2F
Vertical 3F
Overhead 4F