12" duct 25' , in search of a cheaper, smooth, large toriod

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Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

Hello All,

I found a source for 12" x 25' semi rigid duct for around ~ $46.00, shipped.
It only weighs 6 pounds so. we'll see its wall dimensions. I have an idea
how to make a 55 to 60" toroid that should be smooth and strong.

It will take some experimentation, but my intuition says it should work.
It's been nagging me for awhile.and the bubble surfaced. I have some 8"
standard corrugated that I will test the process on.

I have an idea for a better fabric. seemingly from consensus, the weak and
frustrating point in the construction process.

Best Regards,
Jim Mora