Equipment is extremely expensive, then you need a lot of electricity to power it!
Welder currently has a machine capable of welding 1mm wire, requires something around 7kW and another 10kW to cool it! Costs around ?150000 to purchase, and quite a lot to keep it running.
Welding is performed with a laser beam under a gas shield(argon, asfaIk), controlled manually and viewed through a special microscope. Seems anything that melts, can be welded. Wifey has had juwellery repaired when normal brazing isn't possible to apply, close to delicate and sensitive stones and gems.
Heat is kept very local, items like Grants alternator cover get about hand-warm when finished. No distortion to worry about. Big, solid bits do require a bit of pre-heating to maybe 100?C. Typical customers are motor industry and tool machine manufacturers. Also used to fill in casting flaws in turbines, W16 Bugatti Veyron engine blocks

D), rollers, sheet metal press forms, moulds and dies.
A very reputed german auto manufacturer (I think they have 3 rings in their logo, or was it 4?) had a problem on a sports car production line... when the alloy body shell was finished (also welded by robot lasers!), the welding machine would randomly shoot a beam somewhere through the shell, usually in the middle of the roof. Because the large, flat area could not be repaired by conventional welding without enormous distortion taking place, the afflicted shells were scrapped, probably a quite expensive exercise! The factory did not have the facility to repair this, nor was the software fault found, so they contacted my mates company. They now visit them with the mobile welder and repair the 5-6 shells that were holed during the weeks and months prior.
I see lots of quite exquisite stuff in his workshop, exhaust manifolds from Maybachs and Rolls Royce, Veyron engine blocks to monster turbine shafts and press spindles. Lots of vintage/classic bike and car stuff, very often the very last resort, the difference between a static display and a working vehicle.
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