roz, with the cork I use a wood glue, use a piece of threaded rod[ nuts and washes] to clamp the needed lengths
as for eva ,hypalon and even your cork can be done in a lathe.
use wood turning tools for you eva / hypalon[ sharp] if in block form. then sand to suit. if your just trying to size a round piece just sand with a block
by the way ,its good to see you back here
ian