Re: the back of secondary winding

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Scott Hanson" <huil888@xxxxxxxxxxxx>

Aaron wrote:

" I was watching a friend's coil this weekend, and his  secondary 
suffered an interesting yet unfortunate
fate:  All of a sudden, a bright spot of light  appeared on the side 
of the secondary.  After turning
off the coil and approaching, it was observed that a  nice little 
hole had burned in the winding.  It did
not appear to have resulted from a strike or racing  sparks or 
anything quite so obvious."

"His secondary was coated with fiberglass."

When you state that his secondary was coated with "fiberglass", what 
exactly do you mean? Fiberglass cloth or matt, impregnated with 
polyester or epoxy resin? Or just coated with resin, without any fiberglass?
If it was truly covered with fiberglass, was it woven fiberglass 
cloth, or random-fiber matt?
If glass was actually used, can you find out how many layers were applied?
Also, can you find out what type of wire was used to wind the 
secondary? Conventional enameled magnet wire, or something else?
Close-wound, or space-wound?

Always interested in the conditions leading to a failure, and the 
results of the subsequent failure analysis......

Regards,
Scott Hanson