Secondary breakout -is it necessary to rewind?

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

Original poster: "Jolyon Vater Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>


This Tuesday afternoon my 3" x 10 7/8" inch, 880 turn secondary suffered an
intermittant breakout to the grounded end of the primary.

The secondary was being run from my ignition-coil HVDC supply in conjunction
with with six parallel pop-bottle saltwater caps, with the primary tapped at 8
1/4 turns.

Will I have to rewind the secondary? I have examined the area from which the
arc emerged with a magnifying glass and cannot see any evidence of cracked
insulation or burning.

This appears to be an intermittent fault that (as yet) only appears to arise
occasionally when the coil is made to produce large sparks i.e.>5 inches.
Before the "incident" it was my intention to coat the secondary in Tuffkote
epoxy varnish -in view of the present circumstance should I be contemplating
this and is varnishing at all likely to prevent the re-occurance of  an
"occasional" problem of this type?