So that’s what’s under your fretboard!

I thought that I’d show you this photo; it makes sense of what I do with my archtop mandolin necks.

You’ve got the head, neck and two parts of the fretboard extension, each one glued to its neighbour. Under each of the two mahogany capping strips, is a length of rectangular section carbon-fibre. The CF runs from under the head overly as far as is practical in to the fretboard extension.  So firstly, the carbon-fibre unifies all the different elements of the neck. Also wherever you have a joint you can get movement, so the idea of the carbon-fibre is to stiffen the neck and stop any distortion along its length.
The capping strips are bonded to the CF with epoxy and I use them so the fretboard can be glued to the neck’s flat surface with Titebond.