> OK.
>
> Cut a piece of teflon to fit inside a lenght of large aluminum U
> channel.  Make the U channel several inches across the bottom, and
> several more up the side.  A single slot in the bottom of the channel
> allows a couple bolts to pass through the teflon and hold the plenum
> down.  It also allows the tension to be adjusted so that there's no slack.
>
> Thought of that one right after I sent the last message.
>
> --
 Thanks, Ernest

    Sounds simple enough.  I'll look into constructing one that way - cheap
enough for sure.

Ed Anderson