A few basic questions

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Breneman, Chris" <brenemanc@xxxxxxxxxxxxxx>

Like I said in my last post, I'm really new to coiling, and there are 
a few questions that I'm sure are basic but have been bugging me a 
lot, and I can't seem to find the answer.  I'd be really grateful if 
someone could enlighten me.
First, when I tried to check to see if duct tape would break down at 
high voltages (to see if it could be of any use as a dielectric in a 
capacitor), I noticed a blue glow around the edges of the aluminum 
foil that I was using.  I had several layers of duct tape with pieces 
of foil on each side attached to my 60kV ignition coil driver.  I'm 
wondering what exactly is causing this blue glow, at the level of 
electrons possibly jumping shells and photons being emitted, and if 
it's wasting much energy.
Also, I was wondering what effect the size of the secondary has on 
coil performance.  The only thing that I can really think of is that 
a larger secondary would probably have a larger inductance which 
would probably decrease the resonant frequency, but I'm sure there 
are other differences as well, considering that the coils that I have 
seen that produce large sparks are all fairly large in size.
I was also wondering if it would be possible to drive a coil off of 
DC current switched by some kind of mechanical switch, perhaps a 
rotary spark gap.  Like if I had a high-voltage DC source and hooked 
it up to a rotary spark gap rotating at an arbitrary speed and 
connected the output of that to the coil primary.  Would this work?
The reason that I was thinking about this is that I would probably 
try to build a tesla coil with a car ignition coil driven at a 
relatively high (~700 Hz) frequency as the power supply.  I'm not 
sure if this frequency is too high to input directly into the primary 
and was thinking that it could potentially be rectified into DC and 
passed through a high-voltage smoothing capacitor (potentially with a 
resistor in series to limit discharge speed), then connected in the 
way described above.  Would this work?

Thanks,
Chris