New OM build maple neck questions

[Bob Schmidt]

I am building an Octave Mandolin, and the back and sides are quilted maple. I would like to carry the quilted theme to the neck but have some questions.
1. All of the figured maple neck stock I have found is around an inch thick, so I would either have to laminate 3 pieces, or build a scarf joint neck to keep the figure oriented correctly. Is a scarf joint neck common practice for an acoustic OM?
2. If I laminate 3 pieces, the grain orientation goes from a flat sawn to quarter sawn. Would it then loose its figure?
3. I have read that quilted neck wood can be problematic for warping. Would that be an issue with carbon fiber reforcement?

Thanks for any advice. This is only my second build, and I was going to go for a more traditional construction, but I saw and heard a carved top small guitar bodied OM on the web and I was smitten. I just had to go in that direction.

[amowry]

I built a few instruments with quilted maple but had some problems with warping. It's especially problematic if you try to maintain the flatsawn orientation to best display the quilt. Quilt on the quarter looks more like curly maple, though you would at least still have the color match and some degree of the quilt character.

Carbon fiber might help, but I don't risk it any more and use curly red or sugar maple necks instead. It's just not worth it to me. I believe the quilted necks I had problems with did have at least some carbon (it was a while ago). I do see a number of archtop guitars in particular with quilted necks, so some people do it.

[sunburst]

Scarf joints are common in guitar construction, especially classical guitars with their relatively lower string tension. They are not as common mandolin family instrument construction. There is more string tension than classical guitar, but a good glue joint (meaning an excellent fit, freshly prepared glue surfaces, good clamping pressure, etc.) should hold up fine.
Quilted figure shows on the flatsawn surface. There is figure displayed on the vertical grain surfaces but it does not look as "quilted". a neck shaft, more-or-less half round, displays all grain orientation on some part of the shaft. It is actually easier to get quilted figure to show on more of the neck shaft by laminating the neck... if the choice of wood is such that that can be done.
It is not so much the figure that can mean a lack of stiffness and stability in the neck, it is the species of maple. True quilted figure only shows up in bigleaf maple, and that is a soft wood that tends to need reinforcement to stay straight in a neck shaft. Added CF can mitigate that situation, and it is what I would recommend (and have used) in bigleaf maple necks.

I think I would laminate two pieces (with "ears") to form the neck blank and add some sort of CF rod for stiffness and stability. A neck with a center glue seam looks much better to me than a 3-piece neck with two glue joints to each side.

edit:
Pardon and duplicate info. Andrew's post wasn't there when I started this one.

[Bob Schmidt]

Thanks for the detailed replies. It does confirm my concern, and gives me good insight to the issues. If I were to laminate the 2 pieces with an ebony stringer in the center, would that improve the strength or make it worse? The bindings and head overlays will all be ebony. Would you use a truss rod along with the CF?

[Richard500]

Every tree, like us, is a little different. Chances are, you’re fine with something as small as a neck, but if you bookmatch, or mirror, the two outer laminations, you might be a little safer. Figured necks are present on violins, but I don’t know which species are preferred. Even without the cost and supply considerations, woodworkers generally are afraid of the mutants in solid construction. I gave up my appreciation of burls after attending a cancer technical meeting — the microscopic images of very bad things looked too similar.

[Bob Schmidt]

That is an interesting observation. I hope that your attendance was technical and not personal. I will try to find a piece big enough to bookmatch.