Re: New to tesla coils

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Hi Dan,

I second David's comment on spar varnish. I once lived in Minnesota and 
wanted something that would handle temp changes. Spar varnish remains 
flexible and has a hard rubber feel to it. It coats on thick and is easy to 
build a nice coat. It should be noted that should your coil be setup in the 
garage and your wife decides to open the garage door, and should the back 
of the garage door knock the coil over for a major drop to the ground, the 
coating will be damaged. The coat actually peels aways. Repairing a damaged 
area isn't a big deal.

One other bit of info is that some coils seem to build up a static charge 
which coilers have received a few good jolts from. I've never had this 
occur. I've used card board, pvc, and acrylic form types and have always 
used the spar varnish. I highly suspect the outer coating is the major 
contributor to this phenomenon (there have been long discussions on this in 
the past). Spar varnish is quite different than most coatings as far as 
it's internal composition.

When I wind coils, I mount end caps to the form and mount the form 
horizontal. My workbench is fitted with a low speed dc motor which drives 
the coil. Even if a motor isn't used and you simply hand turn the coil, 
mounting horizontally really helps in the winding process. A counter is 
also nice so you know each turn. I usually just set up a prox sensor to 
drive a mechanical counter and mount a metal flag to the end cap which 
triggers each pass over the prox. After the coil is wound, I apply the spar 
varnish with the coil setup in this fashion The motor spins nice and slow 
while the coat is applied. I then let it turn at a very low speed all day 
before another coat. I lightly sand between each coat. I continue this 
until I build up a nice smooth coat. The sanding must be very light. It's 
real easy to sand through the coat and actually sand off the wire 
insulation. This isn't a big deal, but will create shinny areas within the 
winding. For small coils, all this isn't necessary, but sometimes it's 
helpful to hear what others do.

Take care,
Bart


Tesla list wrote:

>Original poster: Tesla729-at-cs-dot-com
>In a message dated 9/28/03 11:26:20 AM Pacific Daylight Time, 
>tesla-at-pupman-dot-com writes:
>
>>No need for glyptal.  Just use polyurethane furniture sealant also found at
>>Home Depot.
>
>
>
>Hi Dan, all,
>
>I agree, although Glyptal probably is the best it is not absolutely
>necessary. I use the Minwax Spar Urethane, which is much more
>resistant to temperature fluctuations than the plain, cheaper urethane
>coatings, which will often begin to crack with age and the wide sea-
>sonal temp changes that most of us in the temperate zone experience.
>The Spar urethane has never done this on any of my secondaries and
>the ambient temp in my shop ranges from 100*+ in August to subfreez-
>ing in January. The Minwax Spar Urethane isn't cheap, about $30 for a
>gallon can at Home Depot, but it's worth it IMHO, and still cheaper than
>Glyptal :^)
>
>Happy coiling,
>David Rieben
>
>