Re: Coilforms, sealants/glyptal (fwd)

---------- Forwarded message ----------
Date: Sat, 11 Jul 1998 01:02:33 -0500
From: "Barton B. Anderson" <mopar-at-uswest-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Coilforms, sealants/glyptal (fwd)

Gotta respond here because I have built my coil using the same tube form. It's basic
sonotube at 12.5" diameter. I used polyurathane inside and out as well as spar
varnish on top of that inside and out after winding. I have had no problems with
this configuration of mixtures.The important note about these tube forms is to
ensure you have seriously sealed the tube from moisture penetration, regardless of
what it is you use. I have not used glyptol (yet) but I'm sure it's a fine sealer
and does the job adequately from others experiences with it. As far as your
fiberglass composite, I think electrically your ok, but moisture penetration would
be the area of concern. Possibly your ok, however, a little "something" prior to the
fiberglass couldn't hurt.

Tesla List wrote:

> ---------- 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 dope
> > marketed in the GC line of TV solvents and chemicals.  Most good electronic
> > jobbers carry the GC line of chemicals.  The other is Aldrich chemical with
> > 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 of
> one of those concrete post pouring forms made of spiral-wound cardboard.  I
> had been planning, if I used that, to seal the form inside and out with Bondo
> fiberglass resin (a two-component product with the 'fiberglass' (?!) resin and
> a hardener which is methyl ethyl ketone peroxide.)  I believe this is widely
> 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 experience
> with this stuff?  Would you go ahead and use 'glyptal' after sealing the tube as
> I described??
>         Thx in advance.
>                                                         Clay