>Skip Slater wrote:
>
>> Brent,
>>    Interesting that this static topic came up right after I asked you on
the
>> phone about the need for static wicks on my ES project.  Since it is a
>> mostly non-conductive airframe, what would your recommendation be for (1)
>> the need for static wicks and (2) how best to make a grounding point for
>> fueling and where you think it ought to be located.
>>    The breadth of your knowledge never ceases to amaze me.  I hope my
>> incessant brain picking isn't a bother, but I can't begin to tell you how
>> much valuable information I've gleaned from talking with you.  I also
can't
>> tell you how much I appreciate your time and patience with what must
surely
>> seem to be some very rudimentary questions.  I'm learning fast.
>>    Best regards,  Skip Slater

Skip:

The only thing that can accumulate a charge and drain it is the electrical
system and grounded metal parts (engine, landing gear, pushrods etc). Be

everything is bonded together with wire or copper foil tape and to the

wicks. Gary Burns had two metal fins (one on each wing) sticking up and

"GROUND HERE", but grounding to the landing gear would be fine too.

If it looks like your fuel probe is close to your filler than I would

ground your fuel ring as well.

Brent

Thanks for the advice Brent,
   One more question though.  When we spoke on the phone about this, I
thought you said that the nose (cowling) could be the source of a lot of
static even though it was composite.  The note below seems to say that it
can't because it's not conductive.  I'm just wondering if I should bond any
copper tape to the inside of the cowling as I believe you told me you did
with yours.
   Thanks again,  Skip

Yes, that was to reduce P-stat and it's associated radio interferance. When a
local charge builds to the point that the surrounding air dielectric is
insufficient, then the air becomes the conductor and the charge quickly
dissapates into the air. The resulting current produces a broadband EM pulse
(like a Marconi transmitter) that interfeers with the COM and NAV radios.
Carbon reinforcements around the air inlets with copper tape to drain off the
charge to the static wicks will help. The reason static wicks work is the
large number of sharp points on the ends. Electrons tend to pile up on points
(a molecular version of surface tension, sort of) and leap off into the air in
a steady flow, reducing the noisey current pulses.

Brent