RE: New 4" coil &Secondary Varnish

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

Original poster: "Aric by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acr-at-infinet-dot-com>

I am quite fond of shellac as a wood finish, but the one secondary I coated
with shellac chipped and flaked to the point of uselessness.  Shellac is a
very hard and brittle finish.  However, as a moisture seal it is one of the
best finishes.  If I ever make a secondary with a Sonotube, I will use
shellac to coat  it, inside and out.

Shellac may be good for the first coat or two when potting windings on a
secondary, as it will penetrate between the windings readily.  I would then
switch to varnish.  Behlen's Rockhard Table Varnish will be the varnish I
use for my next secondary.  It is a high resin (short oil) phenolic varnish
which should build quickley, as it is rather viscous.

Aric

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, September 26, 2002 7:28 PM
To: tesla-at-pupman-dot-com
Subject: RE: New 4" coil &Secondary Varnish


Original poster: "Mccauley, Daniel H by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>



Polyurethane works great as well as "orange" type shellac.  Some people even
prefer the "orange" shellac in the fact that
it doesn't flake like polyurethane when it dries.

Are you sure you want to use two part epoxy?  Seems a bit expensive,
especially for larger coils.

Dan



I'm using two part epoxy & painting it on while the coil jig is rotating.
Two coats. lightly sand and then a coat of varnish to be pretty.  I don't
have patience to wait for all those varnish coats to dry.  Lossy?? maybe you

lose an inch of spark length
Bill Shepard