Official Luthiers Forum! :: View topic - How do you do your mortise and tenon neck joint?

Try a butt joint and save yourself the hassle...

A tenon provides more strength for the neck heel, which is a weak point. And if you bolt on the neck, the bolt becomes a stress point.

John Arnold wrote:

A tenon provides more strength for the neck heel, which is a weak point. And if you bolt on the neck, the bolt becomes a stress point.

Most everyone who uses hanger bolts glues a vertical dowel into the heel first, so that the woodscrew thread of the hanger bolt is located into cross grain , so no end grain issues there.

Also, the dowel reinforces the neck heel in any event, and contributes greatly to strengthening the short grain.

Most everyone who uses hanger bolts glues a vertical dowel into the heel first, so that the woodscrew thread of the hanger bolt is located into cross grain , so no end grain issues there.

Quote:

Most everyone who uses hanger bolts glues a vertical dowel into the heel first, so that the woodscrew thread of the hanger bolt is located into cross grain , so no end grain issues there.

IMHO, both Taylor and Martin use bolts (1/4") that are too large. A 3/16" (#10) or even a 5/32" (#8) steel hanger bolt or screw is plenty strong enough.

So "hanger bolts" are just screw thread stock, I guess.

are you sure that there are 5/32" hanger bolts available in the States ? My understanding was that 3/16" was the smallest diameter commercially available but I could well be wrong.

Author:	mkellyvrod [ Mon Nov 04, 2013 11:56 am ]
Post subject:	How do you do your mortise and tenon neck joint?
To date I've only built (5) classical guitars using a spanish heel (and no truss rod), but want to try a steel string with a mortise and tenon bolt on neck. So what type of jig, if any, do you prefer? I've seen what LMI has and was wondering if most use something like this. Thanks for any suggestions or tips you might have for someone attempting this for the first time.

Author:	SteveSmith [ Mon Nov 04, 2013 1:43 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
I cut the tenon on the table saw or band saw. The mortice I rough in by hand with a router then finish up with chisel and gouge.

Author:	meddlingfool [ Mon Nov 04, 2013 1:44 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Try a butt joint and save yourself the hassle...

Author:	SteveSmith [ Mon Nov 04, 2013 1:49 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
meddlingfool wrote: Try a butt joint and save yourself the hassle... Good point. I've done one of these and it worked very well and easy to do too.

Author:	DannyV [ Mon Nov 04, 2013 2:08 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Chop saw for the neck cheeks (radial arm saw would be better but I don't have one) and a table saw or band saw for the straight tenon cuts. I have it down to minutes and the final fit requires little work............ usually.

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Author:	Nick Royle [ Mon Nov 04, 2013 2:57 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
I did my last one by hand. Best tip I have is to make sure the heel block is all totally square before you mark your cutting lines and drill the holes. I'm still an amateur with a saw but I managed to get a good fit. On my current build I'm doing a butt joint.

Author:	weslewis [ Mon Nov 04, 2013 3:22 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
As Todd says , build neck block with mortise then table saw for tenon, imo ,much easier to square things up, and and one less jig

Author:	Beth Mayer [ Mon Nov 04, 2013 3:50 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
I bought a kit with mortise already in the neck block and didn't get the block in perfectly straight...not off by much but the tolerances for neck attachment are almost nil, so it was a PIA to tweak. I use the simpson mortise/tenon jig (which also comes with templates for a dovetail if you want to try that. It sets the neck angle and allows you to cut the mortise and tenon with a single positioning setup. There's still some neck fitting to do, but if your neck block isn't perfectly aligned/glued, it still allows you to have the mortise exactly where the tenon will go.

Author:	mkellyvrod [ Mon Nov 04, 2013 9:13 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Thanks, everyone for the responses. I have been using Campiano as my main reference on the classicals I've built, so think I'll go with Todd's suggestion regarding the milling of the tenon. I also have Cumpiano's updated approach to a bolt on neck. Also like the idea of a butt joint, so think I'll try this on one also (so far I've work on two guitar at a time). Somehow felt like I needed to use a jig because of the neck angle, but maybe I'm over thinking this; one less jig as Wes said, so I'll see if I can get the neck angle right without the jig. I've got Paul Woolson's plans and can go there if I need to. Thanks, again!!

Author:	Fred Tellier [ Mon Nov 04, 2013 10:02 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
I have only done 4 bolt on necks out of 22 builds and they were butt to the body without m&t and they work great. I actually prefer to do Dovetail joints as that is where my experience is greatest but the bolt on works great. On one I used the method that Rick Michaletti uses for a bolt on neck and fretboard over the body. He sells a Kit of parts and the routing template for this setup, check Luthier cool tools or Rick's web site. Fred

Author:	Trevor Gore [ Mon Nov 04, 2013 10:36 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Martin, I think you have "the book". I use a fixture that holds the body on edge, upper bout down, and pattern route the mortice using a table router. My fixture has a steel base, but wood works fine too. Plans/pics/description are on p 4-46 to 4-48, white book. Deadly accurate.

Author:	John Arnold [ Tue Nov 05, 2013 12:20 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
When I did them, I cut both parts on a table saw. The mortise in the neck block was cut through, before installation. I cut all my dovetails the same way.

Author:	murrmac [ Tue Nov 05, 2013 1:50 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Why is a tenon necessary in the first place ? If you are building as per Bill Cumpiano's updated method, then yes, you need a tenon to house the threaded dowel, but if you go for the Mario Proulx method of using hanger bolts, you can have a perfectly acceptable butt joint, and use the same method as Huss and Dalton employ on their bolt on necks , utilising two stub metal pins for locating purposes. I just don't see what a tenon accomplishes, other than being a somewhat long-winded method of achieving accurate registration.

Author:	Nick Royle [ Tue Nov 05, 2013 3:02 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Exactly what I thought and exactly why I'm doing a butt joint this time!

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Author:	mkellyvrod [ Wed Nov 06, 2013 7:12 am ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Guys, thanks again. Trevor, I do have "the book" but confess I'm still reading the black one. I will check the pages you suggested. In answer to the tenon versus butt joint, I'll admit that the idea of a fitted joint just appeals to me on some basic level, but I'm going to try both. Murray thanks for the heads-up regarding Mario Proulx and hanger bolts, I'll check it out.

Author:	John Arnold [ Wed Nov 06, 2013 12:36 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
A tenon provides more strength for the neck heel, which is a weak point. And if you bolt on the neck, the bolt becomes a stress point. Most of my M&T necks were glued only.....no bolt.

Author:	Beth Mayer [ Wed Nov 06, 2013 12:49 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
What John said. Also, if you use the furniture bolt method, you aren't putting the bolts into end grain wood. The inserts go through the face grain of the tenon and the bolt goes in to those. Less chance of splitting the heel.

Author:	murrmac [ Thu Nov 07, 2013 10:50 am ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
John Arnold wrote: A tenon provides more strength for the neck heel, which is a weak point. And if you bolt on the neck, the bolt becomes a stress point. Most everyone who uses hanger bolts glues a vertical dowel into the heel first, so that the woodscrew thread of the hanger bolt is located into cross grain , so no end grain issues there. Also, the dowel reinforces the neck heel in any event, and contributes greatly to strengthening the short grain.

Author:	Beth Mayer [ Thu Nov 07, 2013 1:22 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
murrmac wrote: John Arnold wrote: A tenon provides more strength for the neck heel, which is a weak point. And if you bolt on the neck, the bolt becomes a stress point. Most everyone who uses hanger bolts glues a vertical dowel into the heel first, so that the woodscrew thread of the hanger bolt is located into cross grain , so no end grain issues there. Also, the dowel reinforces the neck heel in any event, and contributes greatly to strengthening the short grain. Do you have a picture of this, murmac?

Author:	murrmac [ Thu Nov 07, 2013 2:00 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Beth , this is a link to a pic on Frank Ford's site, which shows how Collings do the hanger bolt thing. (you can see the dowel reinforcement as well) . http://www.frets.com/FretsPages/Feature ... ngs214.jpg Admittedly, Collings are using a tenon here, but there is no law against doing a simple butt joint and using the same method ..obviously you have to make your heel a little deeper, but there is no law against that either ...

Author:	John Arnold [ Thu Nov 07, 2013 5:15 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Quote: Most everyone who uses hanger bolts glues a vertical dowel into the heel first, so that the woodscrew thread of the hanger bolt is located into cross grain , so no end grain issues there. Yes, the dowel does help the strength but I still like the extra length of the tenon so that the hanger bolt has more wood to engage. I remember the first time I had a Taylor that had been dropped, pulling the threaded insert out of the heel. I did epoxy the insert back in, but it just looked way too shallow to me....particularly for end grain. IMHO, both Taylor and Martin use bolts (1/4") that are too large. A 3/16" (#10) or even a 5/32" (#8) steel hanger bolt or screw is plenty strong enough. The first banjo I built used a vertical aluminum cross-bolt with two 10-32 machine screws threaded into it. Even with the longer heel, banjos are prone to crack at the hanger bolts, which generally are installed without any dowel reinforcement.

Author:	murrmac [ Thu Nov 07, 2013 6:33 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
John Arnold wrote: Quote: Most everyone who uses hanger bolts glues a vertical dowel into the heel first, so that the woodscrew thread of the hanger bolt is located into cross grain , so no end grain issues there. IMHO, both Taylor and Martin use bolts (1/4") that are too large. A 3/16" (#10) or even a 5/32" (#8) steel hanger bolt or screw is plenty strong enough. Couldn't agree more, John. This side of the pond, 5mm (3/16" approx) hanger bolts have just started to become available. As you say, 1/4" is just too heavy. 5/32" would be equivalent to our 4mm which would certainly be plenty strong enough ...but there are no 4mm hanger bolts available over here ... are you sure that there are 5/32" hanger bolts available in the States ? My understanding was that 3/16" was the smallest diameter commercially available but I could well be wrong.

Author:	Beth Mayer [ Thu Nov 07, 2013 6:52 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Okay, thanks for the visual, Murmac. So "hanger bolts" are just screw thread stock, I guess. I'm more familiar with the threaded inserts some install in the end of the heel or tenon. These https://www.lmii.com/products/mostly-no ... ck-inserts are what I've been using in the last couple builds, and I really like them, but they require a tenon, obviously. It's always fun to see the different ways people do things Sorry if we've drifted away from the OP question a bit.

Author:	Trevor Gore [ Thu Nov 07, 2013 8:04 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Beth Mayer wrote: So "hanger bolts" are just screw thread stock, I guess. Hanger bolts have a wood screw thread on one end (coarse, tapered) and a machine screw thread on the other, to take the nuts. Lots of images under Google Images "Hanger Bolts".

Author:	John Arnold [ Fri Nov 08, 2013 2:09 pm ]
Post subject:	Re: How do you do your mortise and tenon neck joint?
Quote: are you sure that there are 5/32" hanger bolts available in the States ? My understanding was that 3/16" was the smallest diameter commercially available but I could well be wrong. Hanger bolts are also called lag screws.....particularly in the banjo world. Here is one source for the smaller ones: http://www.firstqualitymusic.com/store/parts/banjo-parts/lag-screw-31a-8-32-thread-small-prewar-style/ I have made several of them over the years. I just cut the head off of a steel a wood screw, and thread the plain end with a die.