Re: Best Secondary Surface coating

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Best Secondary Surface coating
From: Tesla List <tesla-at-stic-dot-net>
Date: Wed, 19 Nov 1997 09:15:51 -0600
Approved: tesla-at-stic-dot-net

From: 	Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
Reply To: 	bert.hickman-at-aquila-dot-com
Sent: 	Wednesday, November 19, 1997 8:32 AM
To: 	Tesla List
Subject: 	Re: Best Secondary Surface coating

Tesla List wrote:
> 
> From:   Mad Coiler[SMTP:tesla_coiler-at-hotmail-dot-com]
> Sent:   Tuesday, November 18, 1997 5:01 PM
> To:     tesla-at-pupman-dot-com
> Subject:        Re: Best Secondary Surface coating
> 
> List,
> 
> I am in the process of putting together a new coil and was planning on
> using polyurethane to coat the secondary. Is this a good coating
> material or not? I was planning on coating a portion of the sec form and
> then winding the wire over the wet coat of poly. Then I could coat over
> the top. Another main factor in this is cost (like ~$0). I already have
> lots of polyurethane from doing woodworking. Comments on polyurethane as
> a secondary coating?
> 
> Tristan Stewart

Tristan,

Polyurethane is an excellent coating material. Sealing the coilform
beforehand and letting it dry would be somewhat easier and less messy
than trying to wind the form while wet. Use the clear high gloss type.
The satin finish contains dulling materials that may degrade the
dielectric properties. Besides, the high gloss material looks a lot
nicer. You'll need to plan on putting several coats on top of the
winding. 

BTW, I've also had good success using polyurethane to seal the PVC
coilform, and then coating the completed coil with Behr Build50 2-part
epoxy. Makes for a beautiful rock-hard (but somewhat brittle) thick
(1/32 - 1/16") coating with excellent E-field smoothing characteristics.
You need to be able to keep the coilform turning while the stuff cures -
takes about a day to fully cure. 

Safe coilin' to you!

-- Bert --