After more study I'm starting
to think tightening the wing nut was only part of the problem I was
having with the electric fence being weak.
What I missed until looking
at yesterdays picture was the washer
placement. It seems clear now that more surface area touching the
opposite wire means more charge.
Another mistake may have been
wrapping too many strands, which I think created gaps in the
connection. My new method is a simple bend that wraps around the bolt
without making a complete loop.