Concern using ebony veneer as the center strip in a 3-piece neck.

[fscotte]

Title says it all. I've made my first 3 piece neck for aesthetic reasons. All three pieces dead flat perfect fit, excellent clamp pressure, LMII yellow glue.

Now my concern. The ebony veneer is .020" thick, and as anyone guessed, it's very brittle parallel with the grain, rips like paper. After cutting my neck, I tried breaking some of the scrap pieces by hand and could do it when they got down to about 3/8" thick or less. They all break in the center of the ebony veneer, not a glue problem, but ebony being brittle and all...

I will be using a carbon fiber truss rod glued with epoxy, so it essentially becomes another part of the 3 piece neck. So that should add strength.

Just wondering if my concerns are legit, or is it normal to break a 3 piece with ebony when it is thin enough?

[mtucker]

Title says it all. I've made my first 3 piece neck for aesthetic reasons.

I'm not suggesting you do this, but here's a pic of my mandolin and the faux ebony (painted) strip for aesthetics.

[Frank Ford]

The ebony veneer is .020" thick, and as anyone guessed, it's very brittle parallel with the grain, rips like paper.

You sure it's actual ebony, not dyed veneer? The dyed stuff can be brittle and very weak, prone to breaking just as you described.

[fscotte]

Yes its macassar ebony veneer.

[fscotte]

This is a piece of scrap that I can break down the ebony center. It's about 1/4" thick.

[Paul Busman]

From my whistle making experience, Macassar ebony is less prone to cracking and splitting than the usual black ebony.
I'd think that with the carbon rod epoxied in, and the fingerboard glued on, splitting wouldn't be much of a danger. The string tension will be lengthwise down the neck, not from side to side as in your ebony splitting demo photos.

[fscotte]

Well seems to be a lack of input on this matter. Just seems odd to me, and perhaps it would be normal with such thin pieces, but one thing i've learned in luthiery is, when in doubt, don't. So I made a new neck. A defective neck is a high price to pay for a minimal amount of aesthetics.

[Marty Jacobson]

I've done this on nearly all of my mandolin necks, usually using two strips of ebony veneer and a curly maple veneer stripe or thicker contrasting strip in the center. No problems so far. I would not worry about it. Your test piece is not analogous to the forces in play on a mandolin neck, even during a impact or fall damage.

[Marty Jacobson]

I've done this on nearly all of my mandolin necks, usually using two strips of ebony veneer and a curly maple veneer stripe or thicker contrasting strip in the center. No problems so far. I would not worry about it.
Attachment 153755Attachment 153756Attachment 153757

[John Kelly]

I've done this on nearly all of my mandolin necks, usually using two strips of ebony veneer and a curly maple veneer stripe or thicker contrasting strip in the center. No problems so far. I would not worry about it.
Attachment 153755Attachment 153756Attachment 153757

I'm getting an "Invalid attachment" message when I click on your photos, Marty.

[fscotte]

I've done this on nearly all of my mandolin necks, usually using two strips of ebony veneer and a curly maple veneer stripe or thicker contrasting strip in the center. No problems so far. I would not worry about it.
Attachment 153755Attachment 153756Attachment 153757

My concern was the top of the peghead, since the ebony strip goes all the way through the neck. I am planning on ebony veneers on the face and the back of the peghead, but I was still concerned with the peghead "ripping" apart at the very top, due to the pull of the strings. The thickness of the wood there, minus the veneers, would be about 3/8".

Now you got me wondering if I was being overly cautious. I was really hoping for someone to say, yeah I can break my scrap pieces too..

[Marty Jacobson]

I'm getting an "Invalid attachment" message when I click on your photos, Marty.

Weird. They showed up fine last night when I posted them.

My concern was the top of the peghead, since the ebony strip goes all the way through the neck. I am planning on ebony veneers on the face and the back of the peghead, but I was still concerned with the peghead "ripping" apart at the very top, due to the pull of the strings. The thickness of the wood there, minus the veneers, would be about 3/8".

Now you got me wondering if I was being overly cautious. I was really hoping for someone to say, yeah I can break my scrap pieces too..

I haven't tried it in a while, but any lamination like this with dissimilar woods tends to break along the lamination if there is a large enough disparity in the woods being used. But I don't think a bowing force is generalizable to the function of the neck with balanced forces being applied in its strongest direction, rather than two opposing forces being applied across the most vulnerable axis. To apply those same forces to a neck, you'd probably get it to break too, at the peghead, but it would take some kind of mighty jig with two clamps and a fulcrum to do it.
Plus, with veneers applied, it's reinforced anyway, as you mentioned.

[j. condino]

When in doubt, throw it in the fireplace and make another. Warranty work later on sucks!

[juneman]

I have used the veneer on quite a few necks over the years. I also glued up some test pieces as I also was concerned about stability. I used both tightbond and hhg for the test pieces and the actual necks. I haven't had any problems as of yet and don't expect any. Some of the builds would be about ten years old by now. As you already know tight fitting and a sufficient amount of glue makes a good joint. I think I read a thread somewhere that said always use more glue when gluing a thin veneer between two pieces of wood. Hope that helps

Walter. "JUNE" mandolins and guitars

[Paul Busman]

It just occurred to me that if you were really worried about that thin strip, you could flood it with water-thin CA glue and letting it dry before laminating it between the two neck halves. I think the CA would soak pretty well into the Macassar. This would effectively turn it into a strip of strong polymer/wood hybrid.

[fscotte]

Thx for the tips. Ultimately I've decided to use the 3 piece neck, with Marty's encouragement, it'll be quite strong. It may be a different story if I wasn't using a carbon fiber truss rod. The rod essentially become the center strip since it goes from dovetail and into peghead. I may even extend a short piece of CF to almost the tip of the peghead.

Thx for the CA tip on thin veneer. Good idea for the next one.

[Austin Clark]

It just occurred to me that if you were really worried about that thin strip, you could flood it with water-thin CA glue and letting it dry before laminating it between the two neck halves. I think the CA would soak pretty well into the Macassar. This would effectively turn it into a strip of strong polymer/wood hybrid.

Not a good idea. Neither HHG or yellow glue will stick to the CA impregnated Ebony.

[Tavy]

Not a good idea. Neither HHG or yellow glue will stick to the CA impregnated Ebony.

I confess I wondered about that.

However, if you had good glue squeeze out, and good clamping pressure, either HHG or titebond would be forced into any fissures in the veneer in any case.

[Austin Clark]

I should point out that as a point of interest, that though HHG won't stick well to dried CA, CA glue sticks quite well to dried hide glue. CA loves proteins - this is why it only takes a second to glue your fingers together!

[Cush]

If I want maximum strength when bonding ebony I laminate with Smiths all wood epoxy. A very slow curing formula, this epoxy is made for bonding oily wood. It has the ability to penetrate wood that is too oily for many glues such as PVA glue. It stands the test of time and can be reversed with heat.

[Bluetickhound]

I should point out that as a point of interest, that though HHG won't stick well to dried CA, CA glue sticks quite well to dried hide glue. CA loves proteins - this is why it only takes a second to glue your fingers together!

Unless, of course, you do what I do and let your CA sit around on the shelf for a few years thinking it won't go bad... You KNOW it's old CA when it won't even stick your fingers together any more...

[Bluetickhound]

If I want maximum strength when bonding ebony I laminate with Smiths all wood epoxy. A very slow curing formula, this epoxy is made for bonding oily wood. It has the ability to penetrate wood that is too oily for many glues such as PVA glue. It stands the test of time and can be reversed with heat.

Thanks for the heads up. I've used Devcon 2 Ton (D2T for short...) and had good luck with it. The deal is that while it is a slow cure, once it sets up its irreversible. I mean a jackhammer won't break it. Glad to know there's an alternative.