RE: Coating the secondary

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

Original poster: "Rothman, Aric by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Aric.Rothman-at-Honeywell-dot-com>

I have used shellac for one coil, and phenolic varnish for another.  I would
advise against shellac.  It is rather brittle.  My shellacked coil is no
more because the shellac chipped off, exposing the windings to damage.

The phenolic varnish, however, worked very well.  It is thicker than
polyurethane, so it builds faster.  The slightly golden color it imparts
enhanced the appearance of the windings, too, IMHO.  The varnish has proven
to be very durable.  I recall researching product data for various coatings,
and phenolic varnish had one of the lowest dielectric constants, although
any improvement in coil performance, by way of keeping secondary capacitance
down, is probably negligible.

Epoxy is a more expensive option.  There was a product called Behr Build 50
which several coilers used with good results.  Unfortunately, it is no
longer made.  It was a two part, water clear epoxy.  Another brand still
exists, however.  It is called Pour-On.  A local Ace Hardware here in Dayton
carries it.  

In any case, slow rotation along the coil axis is ideal while applying any
coating, and for epoxy, it is virtually essential.


Aric

> Original poster: "Vince D'Amore by way of Terry Fritz 
> <twftesla-at-qwest-dot-net>" <vincedamore-at-earthlink-dot-net>
> 
> Hello People
>  
>  I know some of you have varnished or coated your secondary 
> with a pour on
> urethane or
> some sort of sealer. Can someone tell me if this improves 
> performance or is
> this just to 
> protect and hold the wires in place? 
>  I have a coil already wound and would like to know if I 
> should coat it or
> leave it as is. 
> If I coat it what product is the best?
>  
>  
>  
> Vince