Current Setting Faults
Welding rod boxes are marked with their recommended current. For my 6013 Murex rods the 2.5mm rods are marked 70 to 100 amps DC, and the 3.2mm rods are 100 to 140 amps DC.
Where in the range you work will depend on the position of the work, but for beginners setting the amps right in the middle of the range should rule out most faults due to incorrect amps.
Amps too low
Setting the amps too low will result in a tall, narrow bead lacking in penetration. The weld will be difficult to start and the arc prone to straying towards one side of a joint in preference to the other.
Amps too high
The bead is wide, flat and irregular, and a small undercut can be seen on the right of the weld in the sectioned photo. A deep crater has formed at the end of the weld, and the slag is difficult to remove from the edges of the weld.
Excessive current should not be compensated by excessive travel speed. This can result in slag inclusions due to rapid cooling of the weld.
Amps OK
With the amps set correctly the bead is a consistent rounded shape, and the slag is easy to remove.
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