Re: Polypropylene coil form

["Malcolm Watts" <M.J.Watts-at-massey.ac.nz> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

hi Luc,
       This makes me chuckle a bit because I had a similar 
problem with a coil which used a skeletal former with a 1/8" 
thick wrap of polyethylene. In fact, a problem of sorts still 
exists. The coil was closewound using 0.9mm wire and heavily 
varnished to minimize the chances of its being damaged due to 
its size and having to transport it in a smallish car. The 
funny bit is that while sitting in a corner in the garage for 
a while, the entire winding slipped in one solid piece to the 
bottom of the former until it was sitting on the garage floor. 
I could probably smash the former and remove it leaving a 
truly skeletal coil behind.
    You could use beads of hotmelt that were "welded" into the 
former top and bottom if the windings were effectively one-
piece.

Malcolm

On 3 Sep 00, at 16:59, Tesla list wrote:

> Original poster: "Luc" <ludev-at-videotron.ca> 
> 
> Hi all
> 
> I have 2 nice piece of 4.5" polypropylene pipe, I want to make coils
> with them . I try to find a stuff to help wire to stay in place and to
> make an interface between polyurethane and coil form . I know all glue
> that become solid can't attach to polypropylene ( and I don't feel to
> ionize the surface, treat it with fluor or use an exotic process ) but I
> note the kind of glue use for tape ( acrylic ?) stay on. Is one of you
> know if this family  of glue could resist ozone and nitric acid from the
> working coil or simply air : I note that the glue on old tape have a
> tendency to dry  ?
> 
> Do you have advice ?
> 
> Tx
> Luc Benard
> 
> 
>