Re: [TCML] Varnish for SSTC secondary

[jhowson4@xxxxxxxxxxx]

Envirotex lite is great, as long as you have a way to keep the coil constantly rotating and the ability to set the speed. 

As far as bubbles go, i have had great luck letting the epoxy sit for a little bit after mixing and then applying it. 
when it is applied monitor it for 30min, first using the blade to get rid of bubbles and ensuring an even coat, then using a heat gun to expand and pop them and finally using a needle to get more resilient ones and smoothing with the knife again. The stuff stays fairly pliable for a good long time, on the order of hours. 

Things to watch out for are having the speed of your spindle too high or too low. too high and you get annular bulges and too low, well i'm not sure on too low because i have not made that mistake, but i would imagine longitudinal bulges. 



Thanks, 
John "Jay" Howson IV 


"Why thank you, I will be happy to take those electrons off your hands." 

----- Original Message -----
From: "Joe Mastroianni" <joe@xxxxxxxxxxxxxx> 
To: tesla@xxxxxxxxxx 
Sent: Friday, February 1, 2013 11:31:11 AM 
Subject: Re: [TCML] Varnish for SSTC secondary 


Ive gone through all sorts of varnishes. Some years ago the Dolph's 
AC43 was highly recommended and I used that. This is an industrial 
material used to varnish transformers. It was difficult to get it not 
to bubble up unless the temperature is held very constant during the 
drying process. I tried several other coatings and eventually I settled 
on a strategy developed by fellow TCML members. 

After the secondary is wound I coat the windings with regular old "Spar 
Varnish" that is easily obtained at any home/hardware store in the U.S. 
This stuff is used on boats and other places where the surface will be 
subjected to water. One or two coats of Spar Varnish will keep the 
windings "glued" in place. 

Then I coat the entire secondary in a thick layer of "Envirotex" which 
is also available locally, but also on line. The Envirotex is poured on 
and smoothed with a blade while the secondary is rotating (very wide 
putty knife works well for this for instance). That dries to a coating 
which is durable. I usually coat to 1/16-1/8" thick, and I apply 2 
coats, allowing for complete drying throughout. So the process takes 
several days. 

The Envirotex is also prone to bubbling if it is not applied/dried at a 
constant temp. 

Pics of my coil winding process available here: 
<http://www.flickr.com/photos/iceowl/5995053288/in/photostream> 

Cheers, 
Joe 



On 2/1/2013 7:29 AM, Atomic wrote: 
> Hi, 
> 
> 
> When I bought magnet wire for my small SSTC I also bought a can of varnish 
> but I'm not sure it's the right one. 
> 
> These are the datasheets but unfortunately they are in Portuguese - the 
> varnish is the Lacktherm 1303. 
> 
> http://ecatalog.weg.net/files/wegnet/WEG-verniz-imp-lacktherm-1303-b-boletim-tecnico-portugues-br.pdf 
> This one says it's a polyester based varnish modified to try on air. 
> Indicated for motors up to 50hp and small transformers and coils. 
> 
> http://ecatalog.weg.net/files/wegnet/WEG-lacktherm-50021432-catalogo-portugues-br.pdf 
> This one says it's alkyd diluent 1021. Also says it's for low voltage (up 
> to 480V) transformers and reactors. 
> 
> The varnish can says it's a modified alkyd rosin, aliphatic and aromatic 
> solvents. 
> 
> 
> Can I sue this? 
> 
> If I can't which one should I get? Note that I don't have a spinning rig 
> and will have to apply it manually. 
> _______________________________________________ 
> Tesla mailing list 
> Tesla@xxxxxxxxxx 
> http://www.pupman.com/mailman/listinfo/tesla 
> 

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