"abripl" wrote in message
oups.com...
Thanks, but that stuff is only flexible for shaping and not rotational
vibration.
Most of those "flexible" ducts have wire reinforcing helix which
resists rotational
motion along the axis of the duct.

I must not fully understand how it is going to be used. How many degrees of
rotation are you thinking it will have to put up with?
--
Jim in NC