Official Luthiers Forum!

The guitar I most often play was built back in the early eighties & I used a CF rod for neck re-enforcement. Because the CF is epoxied in place, I felt comfortable carving the neck very thin, leaving only a millimeter or two of mahogany under the rod.
Since I started buiding again, I have been using adjustable rods. First the home made ones per Cumpiano / Natelson & now The low profile double acting ones.
I have been leaving about 3/16" of material on the back side of the neck & my necks feel a bit clunky. Especially the ones with the higher profile home made rods.
So... Just what is the minimum thickness of material that should be left after carving the neck to shape???
I assume you could go quite thin if you used a very hard lamination in the centre of the neck... But, given good quality Hond mahog with nice straight grain & minimal runout, Just how thin is it safe to go?
Everone who plays my old thin necked guitar loves it & i would like to be able to get a similar shape on the new instruments without jeopardizing the strength of the neck.
Thanks in advance,   Dan

I don't think the strength of the neck is in question as much as the strength of the truss rod support. (if that makes any sense?) If there was less than 1/8'' behind the truss rod, I'd be concerned that it would blow through the back of the neck when tightened.

Paul,

Wouldn't the majority of the stress be pushing the other way, against the back of the fretboard? Assuming the rod is not a dual-action that's set to correct backbow.

Daniel,

If you went with Paul's advice at 1/8", seems the 1/16" would make a big difference.burbank38939.4237962963

_________________
now known around here as Pat Foster
_________________
http://www.patfosterguitars.com

Thanks guys;
I reshaped the offending neck yesterday & ended up with 2.5 mm of mahogany left after final sanding. I removed about two mm of material at the peak & sloped the sides a whole bunch. it made a huge difference to the feel of the neck.
Just for fun (AND to save some time & effort) I'm gonna refinish the neck shaft & heel with Tru oil.
Gotta love those bolt on necks!
Cheers,   Dan

You will like the way Truoil feels. I still lacquer the headstock, but I use truoil for the shaft.

al

Thanks Al; I was a bit nervous about doing the Tru Oil thing, so the encouragement is appreciated.
I was able to scrape nice clean edges where the lacquer is left on the headstock. Have you ever had trouble with the oil creeping under the lacquer & affecting adhesion?
Dan

I don't know. I wouldn't think so, because it hardens rather quickly, and really doesn't penetrate as deeply as you would expect. Ive used it on several electric bass guitars with bolt on necks (no lacquer on these), and 2 acoustic guitars (lacquered headstocks). So far no problems. I only use the bottled Tru oil. The spray stuff appears to be thinned, and I don't like it as well. Buy small bottles as the shelf life is not good once opened.

Al

In the 45 years that I have been using it, I don't think I've run into any finish that would be "eaten" by Tru-Oil. Stay away from the spray,though. It does have a solvent in it not present in the liquid. Store the bottle upside down.I recommend sanding it in-thinned 1/3 to 1/2 with ms and letting the slurry fill pores. I have done a detailed post of this someplace or another;just can't remember where. Anyone wanting details-PM and maybe we can set up phone or I'll try to write it up.MT
Miketobey38941.5011921296

Thanks guys! I picked up the tru oil at our local gun shop a few days ago. The had a bottle of "sealer / filler" made by tru oil too, so i picked some up to try out.
Gotta try it on some scrap first though!
Thanks Again!   dan

Dan,

From accounts I've read, the sealer/filler works OK as a sealer, but not as a filler for lutherie purposes. Shellac would work just as well as a sealer.