Toroid construction

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

I could use some advise from those of you who have made toroids using 
semi-rigid flexible aluminum ducting.  I have two 9" metal pie pans that I 
plan to use back to back, then wrap the ducting around the outside.  When I 
made some larger toroids for the big coil using corrugated plastic pipe, I 
wrapped it around an acrylic center form and cut the ends to join smoothly 
then used nylon lacing cord to tie the ends together.  How do you join the 
ends of the aluminum ducting?  Use aluminum tape?  I planned to use aluminum 
tape to attach the ducting to the pie plates.  I will drill a 1/4" hole in 
the center of the pie plates for mounting on the coil.  Do you also maybe 
rivet the plates together?  Do you stretch the ducting out to its full length 
then cut the ends to fit?  Or, compress it back together, evenly, until it is 
just the right length?

Thanks for the help, Ed Sonderman