I made my trip to Boston and came home with sixteen 300,000uf 15V caps.
The date code was 1984, but they were still in the shipping containers, and I charged each one to make sure they would charge to the 15V level.
Brought them home, and before the car had cooled off, I had mounted 12 of them to my bus bars and gave them a few shots.The test welds look much better,the SCR did not have a problem with the energy, even at the full voltage I did not burn the metal, and the welds were nice and strong.
The only problem with the concept is weld frequency. At 3A of recharge current, it takes half a minute to recharge the capacitor bank between shots. I will need an adjustable voltage 15-20A recharge supply to be able to weld a cell in a reasonable time.
Now I am ready to build the weld head.