I used a pressure washer on the surface of a car at close range. It began to cause static, why is that? here is the video

 

Edited May 20, 201510 yr by Phi for All
embedded video missing

Might be this:

 

These sparks occurred because a) the impact of the high pressure water jets created a fine electrostatically charged mist in the tank space, b) lumps (slugs) of wash water moving across the tank space became electrostatically charged, and c) spark discharges occurred when these contacted projections into the tank space – girders, bulkheads, washing machines, etc.

http://www.chilworth.co.uk/media/124101/TankWashingRisks.pdf

I know that the Millikan oil drop experiment relied on some of the small drops picking up (or was is losing? I forget which ones got measured) a charge when they went through the atomizer nozzle. So there's something going on when you break a small drop into a smaller one, where the drops become charged