RE: filling toroids

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

Original poster: "Ian McLean" <ianmm-at-optusnet-dot-com.au> 

I have used polyester resin before (LSE - Liquid Styrene Epoxy, used for
fibreglassing).  Whilst it works quite well and dries rock hard (I used it
to pot the ceramic capacitors in my NST filter), it does get quite hot
during curing, and also shrinks in the process.

I worry that the polyester would melt an inner tube during curing, and also
shrink out of shape.

Another alternative I just thought of would be an encapsulant.  Something
like isophorone diamine (used to pot MKT capacitors, etc.)  This stuff does
not heat up during curing and does not shrink.  It moulds perfectly (it is
designed to).  Trouble is, it is very expensive.

Also, a toroid made of solid epoxy, of any sort, would be very heavy, yes ?

Rgs
Ian.

 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: Friday, 9 January 2004 1:50 am
 > To: tesla-at-pupman-dot-com
 > Subject: Re: filling toroids
 >
 >
 > Original poster: "Christoph Bohr" <cb-at-luebke-lands.de>
 >
 > Hi Mark.
 >
 > The epoxy tuff inside the alu ducting sounds like a good idea to me,
 > although one has to find a way to keep the liquid epoxy from escaping
 > through the joint.  A very cheap material that behaves very similar is
 > polyester resin that is used for car body reapairs. The stuff
 > smells awfull
 > and looks less pretty when dry compared to epoxy, but is low
 > cost, at least
 > where I live.
 > I wonder how that would combine with tubes from tires. One
 > could fill some
 > epoxy into the tire and then add air to bring the whole thing
 > into shape,
 > then move it around until the epoxy is dry.... That would
 > give a stable
 > lightwight toroid that could be coverd with aliminium
 > tape..... I think I
 > will give that a try next weekend if I can get hold of some
 > cheap barrow
 > tire and a large syringe. First I have to try if that expoxy
 > stuff cures
 > without ventilation and if the rubber can stand any involved
 > solvents....
 > Maybe other liquids work better, but the idea seems better to than the
 > foam.....we'll see.
 >
 > I will post any experiences after the weekend.
 >
 > Sincerely
 >
 > Christoph Bohr
 >
 >