Found an electric motor a friend would let me borrow. It has a 20 rpm output, but I figure d even slower would be better. Decided to make a flat belt drive system. 7" pulley on tank, 3" pulley on motor output. I don't have a lathe, I do have a hyd press and a drill press.
So Morgan and I cut out a bunch of disks.
A little bit of glue and 20 tons of pressure, produced a very rough cylinder. Drill press can act like a lathe if you work on it a bit.