CP Caps (long)

Hello all,

I'm sure I'm not the only member of our list that is following the 
CP-cap saga with great interest. In fact, the promise of outstanding 
performance in a small package certainly got my interest early on, 
especially since so many other list-members were blowing their 
homemade caps left and right just before the first buy. I 
went in and purchased a CP cap on that buy, and I have to admit that
it has performed flawlessly the two times I have run my system with it. 
<grin> All in all, my CP-cap has accumulated a whopping ~6 minutes
of run time since I've had it. The reason: No shop space. In any case,
I found the cap's performance extraordinary, even on my crudely
constructed demo coil. And that's where the problem is.

I use these coils as demo systems for several elementary schools in 
the area, and have shown them for science classes at instructor's 
requests. When I first got the CP cap, I noticed (and as others have 
mentioned) that there was 
no overheating vent, but I naively attributed the lack to 
company-confidence in their product. And now that summer's here in 
America, I'm spending my spare time revamping the systems and 
polishing brass, and the truth is, I just can't risk an explosion 
in a classroom, regardless of the reason. If the CP caps are flawed, 
then there's no question about their use. But if the overheating is 
due to accidental misuse, then who's to say that I won't accidently 
do the same thing? Until this issue is resolved once and for 
all, there's no question about whether or not to use a CP cap in the 

Of course we all know that Tesla-coiling is full of risks, in fact, 
for me at least, that's part of the fascination. For example, if I 
get a small shock that makes me jump forward into a capacitor bank, 
I'm going to get shocked (this happened). If I happen to be connected 
to my coil's terminal, and I tell the guy that's getting this on 
video tape to draw a spark from a piece of metal I'm holding, and 
he's plugged into the wall through his cam-corder, we're both going 
to get it good (this happened too ;)  If I trip and fall into a 
static spark-gap I'm history, probably (hasn't happened :)  If I fall 
into a powerful rotary gap, I could easily lose a finger or two (also 
hasn't happened :). I mean, if I know a capacitor might explode, I'll 
sheild it, try to minimize the danger, etc, *but* those are all risks to 
me, not to others. 

I won't be using the CP-caps in the classroom. 
I'll be using glass-and-foil capacitors. High-loss, but suitable for 
a demo, *and* no risk of explosion. 

About once a year, I get an order for a Tesla-coil. I educate and 
quiz the buyer to minimize the risks. I won't be using CP-caps in 
those coils now either. In fact, it's looking like I have no use for 
CP-caps at all, for the time being at least. If the risk was just 
going to be mine, I wouldn't hesitate to go on with this buy, but I'm 
not the only one that's going to have to deal with fallout (pun 
intentional) should something go wrong. So, I'm withdrawing from 
this last order. I had ordered 3 for this buy, but I'm going to stick 
with just the the one I already have until this whole CP-issue is 
resolved. I *do* however want to thank all those that have so far 
contibuted to the CP knowledge-base, and to Scott and Kevin
especially for all of their above-and-beyond the call of duty 

And thank goodness for this list too, otherwise I could have gone on 
and given a demo and.....who knows what?

Dan Kline   <ntesla1-at-vm.sc.edu>