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

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: David Brown <teslaboi@xxxxxxxxx>

Jim,
I also had a idea on how to smooth-out the duct, by injecting a 
expanding foam inside and controling the expansion by use-ing small 
holes drilled on the inside, never had time to try this..
keep me posted,  I'm looking to make a 12" x  60" Toriod next month 
for a 12 dia x 48" Tesla Coil.

Dave


Tesla list <tesla@xxxxxxxxxx> wrote:
Original poster: "Jim Mora"

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