Carbon fibre (fiber) neck reinforcement

[Alan Hudson]

It's nice to be able discuss ideas with you all. I first subscribed to Frank's site a few years ago and he's helped me with a couple of queries since then. This is my first posting on the forum. I've been restoring old Martin and Gibson acoustics for several years, more as a hobby than a business. My question relates to the neck of a 1942 Martin 0-15 that I'm restoring.
It has the ebony reinforcing strip rather than a T-bar and over the years the neck has bowed slightly under string tension. Since the neck needed a reset anyway (straightening the neck alone would not cure the terrible action), I decided to remove the fingerboard, reset the neck, then re-glue the fingerboard with a very slight back bow, which would straighten out under string tension. However, I'm now considering inserting a thin strip of carbon fibre into the ebony strip to provide extra strength. I've calculated that this will add a few grams to the weight (equivalent to maybe a quarter of an ounce at most) due to the fact that carbon fibre has a slightly higher density than the ebony that it will replace, but it will hopefully make the neck much stiffer.
Is it sacrilege to suggest doing this to a vintage Martin? Or is playability more important? Should I consider putting a truss rod in? I should add that the guitar has been refinished (badly) at some time and has had a really horrible replacement bridge put on, so it's not a collector's piece. I'm making a new bridge out of an old piece of Brazilian rosewood that I have and obviously it will get a refinish.
Incidentally, even with all of these problems, the guitar sounds amazing, and it weighs virtually nothing. I think a lot of modern guitars sound plasticky but this one sounds like a piece of real wood-looking,wood-sounding wood, made of wood.
I'd be really grateful for your comments.
Alan

[Russell Vance]

I'm partial to this approach if it will help and instrument regain it's former glory and provide service well into the future - I've use a lot of the stuff and can't really see any downside - it's out of sight, doesn't seem to affect the tone and is neutral regards weight. It also does not 'sag' over time. However, I also respect the school of thought that advocates making guitars out of traditional material and can accept that carbon fibre/graphite does not belong in that environment. Nice for complex repairs and bringing them back from the dead tho. This is 50 thou unidirectional structural carbon fibre in one of my production necks.Rusty.

[Jim Bancroft]

I've use the carbon fiber(the type sold by StewMac) neck reinforcement in some vintage instruments and it has helped greatly.
I don't see a problem using it on this guitar. Another solution, or in addition to the carbon fiber is to refret with oversize tang fret wire, that will help put some back bow in the neck.

Jim

[Ned Knepp]

As far as I'm concerned, modified and playable are preferable to original and unplayable. I doubt that the future will be concerned about some graphite hidden in the neck.

Ned

[Alan Hudson]

Thanks to Russell, Jim and Ned for your advice. The general feeling seems to be about the same as I was thinking myself. I always like to keep guitars as original as possible, so long as that doesn't interfere with their playability or sound. In this case the improved neck stability provided by the carbon fibre probably outweighs the slight loss in originality. I'm really looking forward to getting this one finished - I've a feeling it will be a great guitar.
Thanks again.
Alan