Re: Fiat PVC, Fiat Lux
There are differing philosophies about the benefits of treating PVC before use.
I did the usual sand, bake, coat, wind, coat thing. My coil's performance is
almost identical to other coils that are just wound and coated. I'm not
convinced that it will effect performance a measurable amount.
One day at work, I ran across a specialist on the molecular diffusion of water
into spacecraft. I asked him about drying and sealing PVC and he said that by
using coating materials available at the local hardware store it would just
matter of time before the PVC reabsorbed as much water as it contained in the
Coating on top of the wound secondary is mainly to protect the wire from
damage. The neatest coating that I have seen to put on top of a finished coil
is called "Pour-On". It's an epoxy mix that goes on thick and heavy. It's as
smooth as glass if it's rotated while it dries and it's so hard that it really
protects the wire from abrasion. Glyptal (made by GE, I think...) is the
ultimate in dielectric coatings, but it's hard to get and well tuned coils
running low to medium power shouldn't have secondary strikes anyway. You may
find some at your local motor rewind store.
You need a plastic cover on the HV end of the secondary to keep the arcs out of
there. Some people swear by the hermetically sealed secondary, but I feel
it is a bit overkill for the small NST powered coils. Many TC construction
ideas are "best procedure" type ideas that make sense in theory but aren't
mandatory for a coil to work.
Here is where I describe my secondary construction and show a pic of my
ingenious $18 coil winder :-)
Making arcs in Huntington Beach, CA
Tesla List wrote:
> Original Poster: Yuri Markov <wmondale-at-hotmail-dot-com>
> I finally got a nice clean 4-inch wide PVC pipe, and 22 gauge magnet wire to
> wind. This new secondary will replace my insult to the hobby of Tesla
> coiling, my 2-inch cardboard wrapping paper tube, 30-gauge wire seconday.
> This time I'm going to get it right. Everything. But first I need to know
> what everything is. So far I've sanded the pipe down to a fairly smooth, not
> at all shiney surface. Should I continue sanding with fine paper until it is
> really quite smooth? As smooth as it was before? Next, I know that I have to
> coat the pipe with something before winding. What is this magical substance
> that I should use? Will it go on nice and evenly, or will I have to re-sand
> afterward? Next, I assume I wind the wire. (Yawn... I wish I had a lathe...)
> Then am I meant to put another coat of the magical coil coating on top of
> that? Sand? Does it matter if it's nice and shiny in the end? How do I make
> sure I don't sand the enamel off the wire? Please help. Also, I am vaguely
> aware that I should make the coil airtight with a plastic disk on each end.
> Why is this necessary? What are the advantages of an airtight coil form?
> And, last of all, can I attach these disks using hot glue, or is that a
> no-no? I apologize if I've asked too many questions in one post. Answers to
> some, or preferably all of these questions would be appreciated and
> eternally helpful. Thank you.
> -Yuri Markov
> Proud owner of a PVC pipe
> Get Free Email and Do More On The Web. Visit http://www.msn-dot-com
Huntington Beach, CA