Thanks guys. At the moment the resultant work is a bit scruffy looking but it can only get better.
John, I am still experimenting with this and will provide more detailed info once I get a little further down the road.
The voltage I am using is adjustable between 1.5 and 2.5 volts and as we all know, at low voltage and high current the enemy is electrical resistance – even a fraction of 1 ohm can create substantial heating as well a voltage drop at the work surface – once I have this sorted I expect / hope to get some improved results. I am showing a reasonably steady 0.2 Amps current draw on the 240 Volt input to the transformer but output current has not been measured. Still not sure about electrodes, I am using copper at the moment but plan to try tungsten as well.
Tweakie.