Cause

  • Travel speed too low (weld metal starts to flow in front of the arc)
  • Travel speed too high
  • Arc voltage too low
  • Too long “stick out” distance
  • Contact tip worn out
  • Insufficient inter-run cleaning
  • Welding in inclining position (downhill)

Remedial actions

  • Increase the travel speed
  • Decrease the travel speed
  • Increase the arc voltage
  • Decrease the stick out distance
  • Replace the contact tip
  • Remove the surface slag prior to next run
  • Adjust the travel speed in relation to the position