"If you get solid core wire (e.g. from a hot-rod shop), which is copper cored. It runs about $.50 to $1.00 a foot (substantially more than GTO15 neon sign wire), but, it is good to 40 kV, and it is much more tough mechanically (particularly when you solder to it: The polyethylene on the GTO15 melts real easily)." Great stuff, but the speed shops around here (LA area) don't seem to carrying it any more, for some reason. Ed