Hi Terry,
Would the smoke & stench matter much if you use a waxed or otherwise
slicked dead tail cone with Andrew's taper and sacrificed a bit of the
tube's end? Would a steady rest help to keep this long tube centered?

I assume you plan to cut the long tube into several segments and I
wonder if a lathe is the best tool for cutting this size tube. How
about bandsawing using a fine tooth blade cutting thru a cross kerf in a
V-sled? Could you dress the tube ends by holding squarely against a
fine grit sanding disc or rubbing plate? You might just want to part
off something on your lathe, if so ignore all this. Arch

Fortiter,