Arc Blow Control Calculator

Diagnose arc blow cause and get corrective recommendations.

Arc Blow Severity by Situation

Situation Severity Primary Fix
Corner/Edge WeldsHighUse AC or wrap ground
Arc RestartsHighAngle electrode back
Deep GrooveMediumReduce amperage
Pipe CircumferentialMediumWrap ground cable
Long SeamsLow-MedMove ground ahead

Understanding Arc Blow

What Causes Arc Blow?

Arc blow is the deflection of a welding arc from its normal path due to magnetic forces. DC welding creates a magnetic field that can be distorted by the workpiece geometry, ground location, or external magnetic fields.

Types of Arc Blow

  • Forward Blow: Arc pushed toward unwelded joint - common at end of weld
  • Backward Blow: Arc pushed toward completed weld - common at start
  • Lateral Blow: Arc pushed sideways - uneven magnetic field
  • Thermal Arc Blow: Caused by temperature gradients, not magnetic

Prevention Strategies

  • Use AC: Alternating current eliminates magnetic arc blow
  • Ground Placement: Position ground to balance magnetic field
  • Electrode Angle: Lean into the direction of blow
  • Reduce Arc Length: Shorter arc is more stable
  • Demagnetize: For severe cases, demagnetize before welding