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

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

Original poster: "Ted Rosenberg by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Ted.Rosenberg-at-radioshack-dot-com>

Dan:
My first secondary was Polyurethane on Plexiglas. Looked nice at first but
it quicly yellowed and became flaky. So, when I built a 6x42 PVC form with
green wire, I wanted to highlight the green column. I chose Envirotex Epoxy,
2-part.

I tested it over and over to be sure I could mix it correctly. To little of
either part results in a coat that never cures. Lots of vigorous mixing
using tongue depressers cut flat at one end. Party drink cups. Clear so you
can see how much you poured in and that part 1 and 2 are equal.

I spun the tube on the motor winder as I poured. I spread it with a wide
polyurethane foam brush. If I had to do it again, I would now use a heavy
rubber blade like window washers use. It spreads a greater amount, evenly
and quickly. Thow it away after.

But the stuff is wonderful when done correctly. Hard as a rock and does not
peal, chip, discolor...oh oh, I sound like a commercial. And all Ace
Hardware stores can get it or you can order direct by web.

Nice people in the customer service group to answer newbie questions too.

Safety First

Ted 

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, September 20, 2002 11:58 AM
To: tesla-at-pupman-dot-com
Subject: Re: New 4" coil: R.Hull and CSN, Secondary Varnish


Original poster: "Writeme Now by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<writeme42-at-hotmail-dot-com>

Hi,

Has anyone ever used enviro-tex as a secondary coating.
Its the stuff they use on bar tops for a rock hard finish.

Cheers,

        Dan


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: New 4" coil: R.Hull and CSN, Secondary Varnish
>
>Resent-Sender: tesla-request-at-pupman-dot-com
>
>Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><megavolt121-at-attbi-dot-com>
>
>Dave
>   My last secondary used a two part epoxy like "varnish"
>called Pour-On. It creats a hard coat as thick as you
>pour on there which protects the windings quite well.
>
>-alan
> > Original poster: "Dave Hartwick by way of Terry Fritz 
><twftesla-at-qwest-dot-net>"
> > <ddhartwick-at-earthlink-dot-net>
> >
> > Guys,
> > What is the current thinking on applying secondary insulation, in this 
>case
> > MinWax gloss polyurethane? There was a time when multiple coats to build

>a
> > up a thick layer was desirable for  corona suppression, racing arcs, 
>etc.
> > Richard Quick was one such advocate.
> >
> > I note that Richard Hull advocates minimum or no varnish at all, stating
> > that pretty secondaries with lots of varnish are also lossy. I've got 
>about
> > 5 coats on the new 4" secondary (#26, 1500 turns) and am thinking that's
> > enough, maybe too much. I've never done A B tests with identical 
>secondaries
> > that differ only in varnish quantity.
> >
> > I also wonder how Glyptal and other substabces compare in terms of
> > lossiness.
> >
> >
> > Generally regarding Rich Hull's work: I'm now reading his Guide to the
> > Colorado Springs Notes--1993, 2nd edition 1995). Here he addresses the
> > secondary insulation matter. He also concludes, for example, that cap 
>size
> > for a given transformer should be smaller than is generally advocated 
>today.
> > He says that a 5kVA 14.4 kV piglet won't handle a 0.06 ufd cap, that 
>0.005
> > ufd is largest a 15/30 NST will power up. This is certainly at odds with
> > more recent LTR methods.
> >
> > The overall question is what is still viable from work generated 8-10 
>years
> > ago? And that goes for any theory that is some years old now. Certainly,
> > much of his conclusions are still valid--Big toroids, magnifier theory.
> > Dave Hartwick
> >
> >
> >
> >
> >
>
>
>