Hi Brian,
The cry for help was intended as a joke, but as you asked....
The supply is in Gary's garage, which is three feet from the side of the house, and I would guesstimate the cable run isno more than 30 ft long. This is a spur taken off the house consumer unit (as far as I can tell), with a twin plug on the wall.
The actual welder (or as Mike correctly identified, 'an inverter') cuts out, giving a very 'weak to non existent' spark, but does not blow the 13a fuse.
After reading the instructions thoroughly (after a few attempts, it's a 'man' think you know), we discovered that the 'inverter' needs a separate 30a supply from the consumer unit, like a cooker / shower would.
He has recently had a modern consumer unit fitted, so that he can (presumably) get this wired up sometime soon, as there weren't any 'spare' 30a connectors available on the old unit.
Mike, as for the cost of the 'inverter', it was one from 'Machine Mart', and so is only a basic one (at that price), which Gary wanted to use in renovating an ageing Triumph Herald that he has on his drive. He thought that TIG would be gentler on the fragile metal, as opposed to the MIG set, which can be a little too powerful on thin sheet steel.
Hope this has cleared things up somewhat gents.
Regards,
Mark.