I don't know about copper, but aluminum and carbon fiber do not go together.  

Why wouldn't the cf work as a grounding plane in its own right? We don't use it for the top shell in solar cars because it is a conductor.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

If the internal resistance of the carbon fibre is too high for a ground plane, there are a couple of manufacturers who make a nickel coated carbon fibre scrim. I have some samples here, but I cannot remember where I got them.I believe the brand name was Thermion or something like that.
A Quote on sales literature,
Main use of copper or nickel coated carbon fibres is for production of composite material with controlled thermal expansion and good thermal or electrical conductivity. Another use is in epoxy laminates to shield electromagnetic waves or to scatter static electrical charge as well as to produce heating plastic panels (surface of airplane wheels, reservoir of fuel and so on).
B.E.

Greetings Napkineng,
Typically mesh can be used in a laminate if it is accompanied with a layer of film adhesive or you can buy some prepreg types (very spendy it's easier to use dry mesh and a film adhesive IMHO).

I would apply one layer of film adhesive to the mold, debulk, apply mesh, debulk again, then start with prepreg plies.

Most applications of this sort are for lightning strike which may not be your issue on the belly of a helicopter (but then I just do composites not an aircraft designer).

Last but not least consider possibly using a foil in lieu of a mesh.  I have applied it in strips on helicopter parts as well and that can be an effective way to carry charge.
Foil is trickier in lay up though.

Hope this helps and good luck.
ps, watch you overlap splices to make sure you get good conductivity if splices are needed.

Composites and Airplanes - what was I thinking?

There are gremlins in the autoclave!

sirs: after much consultation have selected to coat inside with electrodag, seems to be the accepted method. pulled first article, looks excellent

Conductive coatings always look good in articles.  You'll be back after you've tried to make an electrical bond to a coating.

Mike Halloran
Pembroke Pines, FL, USA