Patrick,
The suggestion about the grounding nozzle and brush are good ones. I would
also suggest you get a hand held static field meter and place it the
requisite number of inches from your spray impact point.  If you measure a
significant (e.g. greater than your Vzap number) static field, then you may
need to use an air ionizer to neutralize the charge.  If you do use an air
ionizer, I would recommend the variety that can blow out both positive and
negative ions (self balancing).

Doug Pauls
CSL