toroid for my coil.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Luke" <Bluu-at-cox-dot-net> 

I will be using a 15/60 NST a cap size of about .016 mfd and I have finally 
decided to go the static spark gap route for this coil and attack the SRSG 
later if I get the bug. (thanx everyone for the info there may be a round 2)

I was going to use a toroid of 4" minor dia and about 18" major dai.
I happened to buy some flexible duct from McMaster carr and it is 4 1/8" 
dia but the smallest I can roll this stuff is like a 30" outer dia. would 
this be out of the question for my toroid size?  I would still be at eh 4" 
minor dia so the voltage breakout would be the same (I think)  but I am a 
bit confused as to how to figure out if there will be enough joules 
produced to use a toroid of this size.  Seems there is no exact way of 
figuring this out as a definite.  So thought I would ask the experienced 
ones what they thought.

I like this ducting and really want to use it.  But if there is no way it 
will work with this coil ill have to figure something else out.

Luke Galyan
Bluu-at-cox-dot-net