Re: New 4" coil: R.Hull and CSN, Secondary Varnish

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

I will definitely second what Charles says here!

Coil forms expand and contract with temperature and seasonal weather.  They
can easily shrink enough such that a slight tap will cause all the loose
wire to "fall".  Just a thin coat of spray poly can prevent a destroyed
coil.   guess how I know all this ;-)

IMHO, you "need" something to lock the wire in place and provide at least a
little protection against hits.  I guess we should do some test to
determine if poly or other coatings really do hurt a coil's Q.  Golly,
guess who has all the stuff to do that ;-))

Cheers,

	Terry

At 12:51 AM 8/31/2002 -0400, you wrote:
.....>
>I have a bunch of Richard Hull's tapes, and have seen him use no 
>varnish on some coils, and some varnish on others.  Just a little 
>varnish is usually a good thing.  I tried not varnishing a 6" coil I 
>made in '97.  Once while lifting the coil out of the primary a couple 
>of the windings somehow slipped on the plexi tube.  It was just 
>enough to cause a slight loss of tension.  The result was that 
>several windings skipped over adjacent windings and it was a real 
>mess.  I thought the coil was wrecked and that I would have to rewind 
>it, but I managed to finally get the windings back in place.  Since 
>then I always varnish, even if it's just a thin layer, simply to lock 
>down the windings and keep them from shifting.
>
>Zap!
>
>Charles Brush
>http://www.VoltNet-dot-com
>