professional-looking toroids... home-brew of course:)

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

Original poster: "Mike Novak by way of Terry Fritz <twftesla-at-uswest-dot-net>" <acmnovak-at-email.msn-dot-com>

Hey everyone,

I've been looking for a less costly alternative to spun toroids, and I came
across D&M's page. They sell toroids which are an "economical alternative to
spun toroids", which suggests that the beautiful toroids on his site are not
spun. This puzzled me... I though " how the heck could he get such a smooth
surface, and sell them for less than half the price of a spun toroid the
same size?"... Does anyone know the method used to make these things?
 I thought of a few possible ways:
1. inner tube coated with AL tape and inflated - but that seems a bit cheap
for D&M
2.AL duct coated with resin and covered with AL tape- seems a bit fragile
3. (the way i'm gonna do mine) A AL duct is filled with a filler material
(fiberglass insulation in this case), then sealed as if it were ready to be
used, then injected with a slow-cure epoxy resin at several site by means of
a hypodermic syringe. Once the interior was saturated with epoxy and cured,
the aluminum duct can be pealed off and the fiberglass toroid can be sanded
smooth as glass and coated once again with epoxy to ensure a surface free of
bumps... After a coat of AL tape rubbed smooth by a spoon, you have the next
best thing to a sup toroid- IMHO

The third method seems the most plausible to me, but it's a bit
labor-intensive. I'll try this on a 8"X20" toroid after Christmas, and we'll
see how well it looks...
Any comments?


-Mike