[Prev][Next][Index][Thread]
Re: drying coil forms
The key word was mentioned in your post, Ed, ---- "small machine". PVC and
acrylic is fine for small machines under 300 kV but above this potential
problems can and will occur. Leakage currents build and then breakdown soon
occurs. We have measured these currents and noted their effects and that's
why we don't use acrylic in commercial units. We do use PVC on some but do
a thorough job of sealing the tubes prior to and after winding. Above 350
kV we find PVC unacceptable with daily use. It might be ok for short term
and occasional use but not more severe use such as in musuems.
Like the ad on TV for a certain type of motor oil, the mechanic says, "Pay
him now (meaning the oil salesperson) or pay me later -- the mechanic".
Pays your money --- takes your chances.
Dr. Resonance
-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Wednesday, December 08, 1999 12:26 PM
Subject: Re: drying coil forms
>Original Poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
>
>Ed wrote:
>
>> I have read repeatedly of the necessity of "sealing" the surface
of
>> PVC. While I've never made a TC with PVC pipe for the form, I have made
>> a number of Van de Graaf generators with PVC for the columns, and have
>> never observed any analogous effects. I have a rather small machine
>> here on my desk which starts and runs just fine even when it's very
>> humid or raining outside. Any thoughts?
>
>I have also used PVC tubes as insulators for electrostatic devices.
>In some cases I varnished the tubes with polyurethane varnish, and
>in other cases I didn't. No significant differences were noticed.
>In a Tesla coil, it may be important to remove the humidity because
>the water may absorb energy from the RF fields, but is the amount
>of water in PVC enough for a significant effect? A simple test:
>Operate a coil with a wet secondary and see what happens...
>
>Antonio Carlos M. de Queiroz
>
>
>