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Re: Water absorbtion of Gray PVC - sono tube idea



Original poster: "kayaker" <kayaker-at-sbcglobal-dot-net> 

Hello Everyone:-)

I thought I would add my two cents. I've used this fiber-glass repair resin
with good results. It's called Solarez. You work on your coil under a non-UV
light. Expose the coil too sunlight or sun lamp for three minutes. And your
ready. Here is their website: www.solarez-dot-com.

Doug
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, December 09, 2003 5:07 PM
Subject: Re: Water absorbtion of Gray PVC - sono tube idea


 > Original poster: "pjj" <tha3rdman-at-zoominternet-dot-net>
 >
 > Watching discovery the other week ( think it was discovery) they had the
 > rocket challenge, where the showed how they built the rockets but wrapping
 > carbon fiber around a sono tube then curing the carbon fiber, and soaking
 > the whole thing in water to remove the cardboard.
 >
 > Now at first i though cool a carbon fiber secondary form! but then i
though
 > carbon humm . . .
 >
 > At any rate why not wrap the mag wire around a sono tube heavily coat as
 > most do with lacquer or enamel, then remove the card board and wa la AN
AIR
 > CORE.
 >
 > Just my ramblings
 > Paul
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Tuesday, December 09, 2003 9:48 AM
 > Subject: RE: Water absorbtion of Gray PVC
 >
 >
 >  > Original poster: "David Trimmell" <humanb-at-chaoticuniverse-dot-com>
 >  >
 >  > Hi, I have to agree with Dan here. In all reality a <3Kw coil can
easily
 >  > be wound on un-treated PVC with many years (many hours of total run
 >  > times) of use. I will add, though, that a quick rough up with a coarse
 >  > sand paper, and then hitting the coil with a heat gun to get it warm
and
 >  > immediately spraying it with a acrylic sealant, doesn't hurt!
 >  >
 >  > Regards,
 >  >
 >  > David Trimmell
 >  >
 >  > -----Original Message-----
 >  > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 >  > Sent: Monday, December 08, 2003 5:09 PM
 >  > To: tesla-at-pupman-dot-com
 >  > Subject: RE: Water absorbtion of Gray PVC
 >  >
 >  > Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com>
 >  >
 >  >
 >  > Although your concerns and comments are valid, its really not necessary
 >  > (especially for the mere hobbyist)
 >  > to perform this long process of pre-treating a PVC or other hydroscopic
 >  > forms prior to winding.
 >  >
 >  > Although your intent is good, i feel your comments may actually
 >  > discourage some beginners by making them believe
 >  > they need to go through this seemingly overwhelming pre-treatment
 >  > process.  This is especially true considering the
 >  > comments come from the two most experienced tesla coil firms, Resonance
 >  > Research Corporation and KVA Effects.  The beginner
 >  > may believe these firm's comments may hold more water so to speak than
 >  > the other people on the group.
 >  >
 >  > The important points I think should be made are the following:
 >  >
 >  > 1.  Yes, hydroscopic secondary forms such as PVC will benefit from a
 >  > pretreatment process as described below especially
 >  > in higher power tesla coils (5kW + )
 >  >
 >  > 2.  For most small power coils, there is no need to pre-treat the PVC
 >  > secondary.  This is based on the experience of many of the members of
 >  > this list including myself.  I'm sure if you took a poll, the number of
 >  > people on this last that go through the elaborate process of
 >  > pre-treating a secondary prior to winding will be greatly outweighed by
 >  > the "just wind it" and go people of the list!
 >  >
 >  > Many people on this list will claim sonotube or other cardboard forms
 >  > are the worst possible material for a secondary form
 >  > and should be avoided at all costs.  However, the best coils i've ever
 >  > seen were built with cardboard forms.
 >  >
 >  > Dan
 >  >
 >  >
 >  >
 >  >   > TCML,
 >  >   >
 >  >   > I have to back Dr. Rez on this one guys... We use PVC and
 >  >   > fiberglass forms.
 >  >   > We have accumulated hundreds of hours of run time on a dozen
 >  >   > or more PVC
 >  >   > coils all above 10kW. We have a really burnt PVC form we keep
 >  >   > in the shop as
 >  >   > a trophy...
 >  >   >
 >  >   > Sand, bake*, seal...
 >  >   >
 >  >   > Sanding breaks up the surface. HV arcs love to travel down
 >  >   > smooth surfaces.
 >  >   > We use coarse grit and leave the final finish rough. After
 >  >   > surface prep and
 >  >   > careful and gradual baking with tungsten strip heater, seal
 >  >   > the PVC with
 >  >   > commercial HV varnish. There's more to the process but those
 >  >   > are the basic
 >  >   > steps hobbyists should follow.
 >  >   >
 >  >   > Will you coil work the same if you don't follow these steps:
 >  >   > sure! Same
 >  >   > applies to O-rings and spray-on foam insulation.
 >  >   >
 >  >   > * don't over do this step. 20 degrees above ambient for two
 >  >   > hours is all
 >  >   > that is necessary IMO. If you use heat lamps, spread them
 >  >   > out, put them on a
 >  >   > variac and don't put them too close. "Hydroscopic" doesn't
 >  >   > mean it's full of
 >  >   > water and you have to dry it out.
 >  >   >
 >  >   > Jeff Parisse
 >  >   > kVA Effects
 >  >   > www.teslacoil-dot-com
 >  >   >
 >  >   >
 >  >   >
 >  >   > snip...
 >  >   >
 >  >   > All PVC is hygroscopic especially when used at high
 >  >   > frequencies. It's best
 >  >   > to sand interior and exterior, then paint with 3 separate of
 >  >   > Glyptal or
 >  >   > other HV insulation. Interior sanding is rapidly accomplished
 >  >   > by using a
 >  >   > sanding "flapper" on a dowel (or other extender) on an electric
 >  > drill.
 >  >   >
 >  >   >
 >  >   >
 >  >
 >  >
 >  >
 >