Ah the good ol’ days... I was a steamfitter welder at plants 1,2, & 4 and we used to complain about the crappy welds on the prefabbed pipe all of the time. Of course our welds had to be perfect (100% x-ray) right next to a weld that had porosity, wires sticking through it, and blow holes, (basically name the defect and it was right there) and the QC/QA would do nothing about it.
As far as welding rebar, the Ironheads were certified CAD welders to splice rebar together. Basically a special coupling that is placed over the ends of both pieces and electrically charged to weld the two together. Lots of big sparks when they did that...
Cad welding is done with gunpowder.
Electricians also use the pots for ground cable.
“Ironhead till I’m dead!”
The FAA had a couple of field techs who loved it when they got a thermite job at one of the sites.