Original poster: David Speck <dave@xxxxxxxxxxxxxxxx> Peter,It's likely that grounding of the case is not the problem. Your body is acting as an antenna, and you are getting shocked when you touch the metal case. I've had this problem when working in relatively close proximity to some of my coils. The solutions are to put a Faraday cage around the coil, or at least a grounded screen between yourself and the coil. As an alternative you can install insulated handles on the coil controls so you don't ground yourself when you touch it. I had a particular Variac that would bite my thumb whenever I tried to adjust it, because the setscrew in the knob was close to the surface of the plastic.
Dave
Grounding is still not settled. There was a problem with shocks and sparks from the metal case. I found this defective capacitor and parallel resistors connecting the bottom of the coil to the metal case. This in turn was connected to the ground wire on the power cord. I disconnected the capacitor and tried running the bottom of the coil to an earth (water pipe) ground. Also tried connecting both the coil and the case to the water pipe ground. Never could get the case where it could be touched comfortably. I'm beginning to think it just can't be done to due induction effects and limitations of water pipe grounding.