There was a question from someone about carbon static wick conductance and I said I'd check my records.  I did some tests awhile back but didn't find my old notes, however I did repeat some tests of two coupons I had laminated previously.  This lights up my life which is a sad testament to what I enjoy, but I digress.  Here are the numbers:

 

 

Derakane 8084 toughened vinylester resin for both specimens

Laminates are 10 layers of unidirectional carbon .033 lbs/sq. ft. dry, 33 million modulus

measurements taken from #8 self tapping SMS through laminate except for 90 degree surface measurement which is taken from sanded carbon surface

screw pattern: 4" x 4"

 

 

Specimen #1, vacuum bagged laminate molded to plate glass surface

 

finished weight, .618 lb/sq. ft

thickness .089"-.102"

resistance at:

 0 degrees     6.1 Ohms

90 degrees     19.3 Ohms

45 degrees    21.3 Ohms

 

 

Specimen #2, Open layup carbon, squeegeed finish on top, molded to plate glass surface

 

finished weight: .80 lbs/sq. ft.

thickness .125" - .160" (Note: much more texture since fibers were free to lift on open side)

resistance at:

0 degrees:    15.2 Ohms

90 degrees    208 Ohms

45 degrees    168 Ohms

 

90 degree surface measurement:    670-1800 (open surface side)

As you can see, the conductance is pretty good.  I will try to find my previous tests of the hull laminate readings or at least repeat the readings from the boat which is more realistic since the laminate is in three different directions.  These will be from the inner skin.  I'll post them later.

 

Dan Newland