Here's info how I made my latest cf neck.
First I laminated a T-beam for trussrod and top of the neck. About 2mm wall thickness.
Then Divinycell foam was glued to the beam and shaped to correct shape minus wall thickness.
Small fillets to the corners of beam were made. CF epoxy filler shows in grey on this pic. Then it was time for 3mm cf skin. Vacuum bagged just like before.
Trussrod fitted, Richlite fretboard glued with epoxy, then epoxy filling, sanding, more filling, sanding... fretting, fretwork etc as usual. The saddle end shows nicely what's inside the neck. Saddle end filled with cf filler for headpiece inserts.
Body made of alder, 10 coil pickup with ACG EQ2 filter preamp, ETS hardware. Body and neck finished with 2k acrylic.
The sound: Well, this one has no doubt the most articulate and strongest b-string sound I've made so far. Let your ears be the judge how you like it. http://maihinnousu.net/s/20408