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After making 70+ instruments, experimenting with different neck joints, I finally settled on a strait up butt joint bolt on neck.
I love it. So simple. So easy to set the angle and get a nice flush joint.

Why don't I hear about more builders doing this?
What's the point of a T/M if it isn't glued up?

tia
dave

Hey Dave, good to see you’re still around. I just quit doing dovetails with one I finished two months ago. For the one I finished last week I used an M/T bolt on. I’ve done a few butt joints in the distant past. I honestly don’t think it matters.


Steve

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Steve Smith
"Music is what feelings sound like"

300+ bolt on butt joints since 2008 and I ain’t looking to change…

That's by far my preferred method.

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Guitar Maker and Purveyor of the World's Finest Tonewoods
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I have been doing it the last 10 or so. Works great. I especially like flossing/fitting the neck in one shot rather than doing side to side.

I did however just buy a m&t jig because I want to try some with a much thinner heel where there might not be enough meat for an insert.

Sent from my SM-N960U1 using Tapatalk

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Pat

That’s the one concern I have about bolted butt joints: Has the builder left a big enough heel to handle the stresses? Assuming the answer is yes, I think they are great. Easy and functional.

I’m currently experimenting with the Gore/Gilet bolt on, bolt off neck attachment, which I love so far, but the bolted butt joint with glued fingerboard extension is definitely the easiest of neck joints to get right, and it works great (assuming the heel is not tiny).

You can also do a neck reset in 15 minutes without even having to unglue the extension.

Funny you should mention. I just received twenty-five (3/16) hanger bolts with washers and nuts. Now I'm trying to decide on how to do the wood threaded end. Maybe drill a pilot hole and then 1) use some ca glue to harden the wood and then screw it in or
2) use structural epoxy in the pilot before screwing the bold in.

Primary reason I kept the tenon is that I like a narrow heel so the tenon gives me some extra strength for the bolts.


Steve

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Steve Smith
"Music is what feelings sound like"

I have been doing the old school Taylor bolt on butt joint for 20 years now probably. The only time I don't do it is when I'm making something like a Maccaferri style heel which is very thin so it requires the M/T joint to hold the barrel nuts.

Yes, about the only possible drawback to this joint I have seen is that there is short grain at the shaft/heel transition, which can weaken this area, depending on other details of the geometry. I use it often, except for historical reproductions and in the case where additional strength here is clearly needed. (The instrument currently on my bench is a Chitarrone Toscano, a 19th century Italian upright contrabass guitar. I'm using a thick and deep tenon on that one just to add more wood here, because the body is so massive.)

The butt joint is also what I recommend for beginners in my guitar building book. The requirements of lutherie and lutherie pedagogy don't necessarily overlap perfectly, but this is the joint I have seen first timers have the least amount of trouble with. This is particularly the case for first time builders working without the benefit of an experienced builder looking over their shoulders. BTW, the book makes use of simple sanding board templates for fitting the neck to a body that has a flat surface to mate with the heel. Anyone interested in those templates can download them here: https://liutaiomottola.com/download.htm ... ates%20pdf. If you see them it will be obvious how they work.

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R.M. Mottola
LiutaioMottola.com

Author of the books Building the Steel String Acoustic Guitar and Mottola's Cyclopedic Dictionary of Lutherie Terms.

Glue a cross-grain dowel up the length of the heel to make it split-resistant and give some side grain to screw into.

I do use CA when I need wear-resistant threads in wood, but I form the thread first and then harden, since CA is brittle so it would probably get all crushed up in the thread forming process and lose most of its benefit. And it's not great for strengthening endgrain threads since you're trying to boost shear strength and CA is weak in shear.

If you ever need strong threads in endgrain and don't have the option of a cross-grain dowel, I've had good results forming them entirely out of epoxy/wood dust mix. Drill the hole oversize, coat inside with pure epoxy which will penetrate, then add some wood dust mix. Coat the screw with grease and then wood dust mix, and stick it in. After it sets up you can take the screw out.

For a screw that you don't ever need to take out, it would probably work just as well to screw it in with wet epoxy like your idea #2. It should soak into the wood and bind the fibers together the same as it does with the dust. Just can't coat the screw with grease or it would get mixed with the epoxy as you screw it in and probably wouldn't set up properly.

If you leave a tenon and if you glue that tenon be aware that Martin's glued mortice and tenon joint does fail and we see them after they fail. The heel develops a gap with the body that is visible from the outside and the neck angle starts to change. This is a single bolt system.

The cause is the glue joint is in shear and then it fails. This is very common we see it frequently. It's also covered under Martin's excellent warranty.

So the glue in a M/T butt joint is questionable if it's necessary anyway especially with you guys using multiple bolts and do what it takes to firm up where the inserts are.

Nothing wrong with this method or joint that's not my point. My point is that glue may be a waste of time and effort.

One way to give the appearance of a thinner heel, while using a fairly robust bolt on joint is to "pocket" the heel so it extends into the body. This can also allow you to create an adjustable angle neck that may never need a re-set. I do that for my travel guitars where the neck is removable, but there is no reason it couldn't be done by making the adjusting bolt adjustable from the neck block side.

This is one of the first posts I've made in a long time where I didn't feel totally dum after the comments started flowing in.
I know I opened it up for criticism.... but this is good. I like it when someone else thinks I have a good idea.

What made me feel dumb was realizing how much time I’d wasted making dovetails and the usual variants of M+T and bolt off and on joints before discovering just how simple and effective the bolt on butt joint is…

My suggestion is to use threaded inserts and not hangar bolts for anyone who wants to give it a go. Makes resets a breeze…

I did mortise and tenon joints on my early guitars (1977 to 1986). I did not bolt them, and not one has failed. IMHO, the reason Martin M&T joints fail is because of the loose fit.
Whenever I do a reset on one of those Martins, I always shim it to create a tight fit.

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John