Very neat. I tig weld some when I can see (not the best). I am wanting a conical fermenter so bad here. I have one batch in a carboy, another 11 gallon in a plastic food drum.
I was thinking of a pin-or-ball keg thou instead of a 1/2 keg.
Neat idea on the pipe "gradual" increment bender, a "gocart" tire in a press (or ewheel frame) over a rounded lower roller will also "bend" the metal into a arc conforming to the lower roller. I learned that on Metalmeet.com from some good guys. (metalshapers)
I have a small slip roll here. The rollers need cleaning, it imprints the rusty surface onto the stainless.