I have a new hobby. Classic car restoration. If you are interested in that sort of thing you can follow my progress on my blog Haugland spitfire rehabilitation centre. I am having to learn a lot of new skills like welding. I'm using a flux core wire on a MIG welder. A transformer steps down the mains voltage from 220 V to about 24 V. The current goes up proportionally so there is something like 100 A passing through a  0.8 mm diameter wire, this gives a lot of heat causing the wire to melt. Such high temperatures give rise to em radiation in the UV range so you have to protect your eyes and face. I bought this helmet with a glass panel that darkens automatically when you strike an arc. I guess its a LCD panel that is activated by light being absorbed by a photovoltaic cell. Works pretty well, it means that I can see the work both before and during welding.