Got Shocked

I have seen pics of other people doing this so I tried it myself.  Take a
look at this pic and you will see what I mean,
http://members.aol-dot-com/krampf/watt.html. I got zapped. I have done this with
a VDG several times but this is the first time with a TC. I stood on a 5
gallon plastic bucket, the plastic bucket is my insulator.  I turned on my
750 watt TC and set the variac to about 150 watts.  I can get 6" sparks to
my hands and fingers but I can not feel them at all.  I turned the power up
some more and still I can barely feel a 18" sparks.  With my hand on the
toroid I can not get any sparks to radiate off of my other hand into the
air.  Tried retuning the TC but still can not get any sparks to radiate from
the other hand.  I turned the power down to 150 watts again and with one
hand on the toroid I held the other hand out to a target.  ZAP, knocked the
-at-#$% out of me. Glad I had the power turned down.  I know by touching the
toroid with my hand my body acts like a top load and changes things so the
primary will have to be retapped.  I don't think I will try this again until
I learn how its suppost to be done. Does anyone know how this works?  I am
gun shy now, not sure I want to try it again.

Gary Weaver