[TowerTalk] Vertical antenna material suggests

[n0tt1 at juno.com]

Hi Gents,

Looking for suggestions for the materials to
build a "permanent", self-supporting 40m vertical ~33ft high.
Will use several in an array such as a 4-square.

What has worked for you in windy areas that's relatively
inexpensive?

Thanks,
Charlie, N0TT