Re: Coilforms, sealants/glyptal (fwd)

---------- Forwarded message ----------
Date: Sat, 11 Jul 1998 10:36:44 -0600
From: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Coilforms, sealants/glyptal (fwd)

to: Clay

If you are using the sonotube --- don't bother with the Bondo.  Just apply
3 coats of Glyptal inside and outside and then wind.  Apply 3 more light
coats after winding and fire it up.  Glyptal was originally a very high
rust proof coating applied to barns and other outdoor sheds until someone
at General Electric noticed its excellent electric properties.  GE bought
the company, tripled the price, and started selling it to electric motor
shops.  It has excellent resistance to moisture and very good electrical
properties.  We have used it on many of our coils and still use it now on
the upper and lower 2 inches of the ends when using PVC insulated wire.  We
use 2-3 coats of Bullseye shellac (clear) on the main part of the coil.  We
don't use it for insulation value -- only to make the overall appearance of
the finished coil very "shiny" and more attractive to our customers.  Many
of our earlier coils we used Glyptal top to bottom -- it works great and
will work on your sonotube but skip the Bondo -- not necessary and might
make for some power factor problems.


> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Coilforms, sealants/glyptal (fwd)
> Date: Friday, July 10, 1998 10:27 PM
> ---------- Forwarded message ----------
> Date: Fri, 10 Jul 1998 14:26:53 -0500 (CDT)
> From: Larry Bud Melman <gasman-at-althea.a-line-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Coilforms, sealants/glyptal
>  {snip}
> > Glyptal is available from two sources I know of.  One is the red corona
> > marketed in the GC line of TV solvents and chemicals.  Most good
> > jobbers carry the GC line of chemicals.  The other is Aldrich chemical
> > still offers it. (expensive in block form)   Glyptal is not as good as
some of
> > the more modern low vapor pressure materials like Inland seal, 
vac-tite or
> > others.
> > 
> > Richard Hull, TCBOR
> 	Richard, and other glyptal advocates:
> 	I'm a little cunfused about glyptal - only heard of it a couple of posts
> ago.  What is the nature and design purpose of the stuff??  
> 	Do you contend that all coilforms should be sealed inside and out with
> it, or just cardboard and other forms with 'poorer' electrical qualities?
> 	I ask this partially because I'm having trouble finding a coilform as 
> large as I want, and I've been considering just doing a 12 inch one out
> one of those concrete post pouring forms made of spiral-wound cardboard. 
> had been planning, if I used that, to seal the form inside and out with
> fiberglass resin (a two-component product with the 'fiberglass' (?!)
resin and
> a hardener which is methyl ethyl ketone peroxide.)  I believe this is
> used for auto body repair.
> 	I don't know anything about the electrical qualities of the material.
> I chose it because it will make the cardboard tube rigid enough.  Any
> with this stuff?  Would you go ahead and use 'glyptal' after sealing the
tube as
> I described??
> 	Thx in advance.
> 							Clay