Re: Pre-Treatment for Sonotubes for Secondary Coils? ? ?

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 9/6/02 6:26:00 PM Pacific Daylight Time, tesla-at-pupman-dot-com
writes: 
>
> Three coats Glyptal or Dolph's ER-41 both inside and outside and you are
> ready to wind.  The Glyptal seals the tube against atmospheric moisture,
> which, if absorbed by the tube, will cause the "release" agent to activate
> and the tube swells and upspirals.  The release agent is incorporated into
> the tube for their intended purpose --- releasing when soaks with water
> after the concrete has set up.  These insulations are much better dielectric
> than polyurethane and they don't crack or flake as time goes by.
>
> Dr. Resonance



I had always used polyurethane, but in the last few years I've been
using the "spar varnish urethane" which seems to make a much 
better and more durable coating than plain urethane. Incidently,
where does one get Glyptal or Dolph's ER-41?

David Rieben