secondary insulation

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

Original poster: "James by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mustang3-at-cox-dot-net>

Hi list,
    I agree with John, my research has not shown heavy secondary insulation to
reduce performance. On one of my first secondarys, I used PU varnish (many,
many coats). EVERY time I would get racing sparks, big chunks of varnish would
be blown off. I have also had 1 racing spark blow a hole in the coating and
burn the wire in half. Now, I use a thick (2) coats of that 2-part stuff. West
Marine has an epoxy coating that works well, so does HD and Lowes. Now a minor
racing spark doesn't make a hole in the insulation. As I was writing this, i
was thinking, Why would extra insulation hamper performance? If the wire had
extra thick insulation, the tpi would go down. This however is only a minor
tuning issue. The insulation is not magnetically shielded(mu metal). I don't
see how 1/4 to 1/2 of fiberglas would make much difference. Might trap the
heat.
    In closing, I feel the prevention of racing sparks is the most important
aspect of the secondary insulation. My Tesla coil changes all the time. I
seldom run it the same way twice. Big toploads, big caps (yea Sundog), you know
let's tinker with it. I keep notes and try never to blow it up the same way
twice.
                                                                           
                                                    Later,
                                                                           
                                                        James