RE: Safety gap and first light

> For 15kV you need *AT LEAST* two
> layers of 60 mil poly, perhaps 2 caps in series or even 2 of two layers
> of 40 mil. 
Piffle. You do not need that much dielectric! However, don't be crazy
enough to try and run 15KV in a single cap. I have 2 "caps" that I run
at 14.4KV from my pig. By cap, I mean multiple plate caps in a single
enclosure. One (that just got retired by a fumble fingered student, you
cant drop a cap 2ft to concrete and expect the seams to hold well :/) 
was constructed of 3 units of 5x6mil (30mil) spaced dielectric in series, 
paralleled with 2 units of 7x6mil(42mil). This cap served me well for
2 years. The other is constructed of 3 units of 5x6mil. This cap
is still going strong after 18months. I am in the process of constructing
a third unit the same way (to replace the destroyed one :/). Run time
on these caps is currently in the 40 hour range.
Remember, the killer is overvoltage on each unit. In these caps, no
cap sees in excess of 5KV AC (rms).