The other day I was watching an episode of Mythbusters in which Jamie
used hydroforming to fabricate a pontoon out of stainless steel.
(Sorry I could only find this in Spanish)
https://www.youtube.com/watch?v=sxcOzPzqOi8Is there any reason that we couldn't use the same technique to create
toroids? It would seem that all one would need is three thick pieces
of steel plate, a large outer ring, a small inner disk and a large
bottom disk. A pressure washer would provide the necessary high