Factors Affecting the Arc
An arc between a bare metal wire and a metal surface is unstable and wanders all over the weld pool - needs to be stabilised
- Flux evolves gases which stabilise the arc
The arc cannot be maintained with voltages less than ~14V and above 45V becomes unstable
- Use a specially designed welding supply
Magnetic fields - Lorentz forces can be generated which move the arc by currents induced in the parent metals - arc blow