# Instruments and Equipment > Builders and Repair >  Bolt on neck method

## Jim Baker

I recognize that most builders frown on a bolted neck joint, but let's just say for a moment that we all recognize it as an accepted method, what is the best hardware to use?
My stewmac campfire kit came with a 3/16" lag stud but I have read of using a glued in insert in the heel and threading into that.  Are these inserts available?

Any opinions?  Thanks.

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## Jim Baker

Perhaps to answer my own question I did find such an insert at McMaster Carr. 

http://www.mcmaster.com/#catalog/116/3267/=6egnhl

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## big smiley guy

On guitars I've always used a bolt on neck using threaded inserts.  Most "real" hardware stores will have a selection to choose from.  I use 1/4-20's for guitars but there are smaller sizes available that might work better for a mandolin.

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## Jim Baker

Thanks Smiley. I'm thinking 1/4-20. I looked at some hardware stores here. I haven't checked Lowes yet. Lee Valley has lag studs that are used as funiture hardware, but I think I like the idea of an insert.

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## bennyb

Howdy Jim,
I haven't done any bolt on necks yet, but I'm thinking about it.  I'm probably going to copy mottola's technique.  He's quite specific about the hardware.  (Maybe you already know that site?)

benny

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## Charles E.

Jim, here is a mock up I use on my instruments using knock down furnature hardware. Screw inserts dont like end grain maple. Screws and 10mm barrel nuts as well as screw inserts are available at Home Depot and Lowes

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## billhay4

Charles E. has it right.
The barrel nuts are a better solution IMHO.
Bill

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## Jim Baker

Thanks guys. I do like the idea of the barrel nut. I will check to see that I can make it work. I could easily make one if I can fit it in. The hole would need to be drilled blind from the top down I'm thinking. 
Since I will be using 2 bolts I should make one barrel nut with two threaded holes I assume.

Benny: Good information. I will check to see if I can get that type of insert.  If I can get the inserts they would be easier for me to install.

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## Charles E.

Jim, with the barrel nut you drill it from the neck heel, not the top. the hole is then covered with a heel cap.

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## Rob Grant

Why?

I can imagine a slight advantage with a guitar since a neck reset is a fact of life with most guitars, but why a mandolin?

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## pelone

Jim---I have used the McMaster Carr slotted  drives on a mando as commented upon by Smiley and Benny B.  I found, as Mattola shares, that a secure anchor is created when inserting 2 of the drives in the pilot hole and then backing out the bolt results in a nice alignment when the hex headed nut is  then used from the sound chamber side.  I further used glue to insure a solid and secure anchor.  I have not had any separation at the heel due to tear out in end grain maple as mentioned by Charles E yet but perhaps I am just fortunate. However, the end grain concern/problem does occur to me to be valid and consequently I will likely use the barrel nuts as the method seems to be simple and elegant. I like the barrel nuts.

I suppose that "traditional" builders do not approve of bolts because it was not done that way historically speaking and metal bolts seem to be counter to the trade.  However, if metal were that onerous we should then abandon metal strings, metal tuners and heel plates. Please post photos of your project if possible.  Happy Building.

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## Jim Baker

Thanks guys. My project is a 21" scale octave mandolin. Engleman spruce and big leaf maple. I'm just at the stage of completing the neck joint and I need to fix the neck so I can verify the angle.

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## Charles E.

Jim, that looks great!
A good friend and fellow builder were dicussing using an elongated 1/4" hole in the neck block of an octave mandolin with a floating fingerboard extension. You could adjust the height of the fingerboard over the body to affect the string heights. He built at least one instrument that way and said it worked well.

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## Charles E.

> Why?
> 
> I can imagine a slight advantage with a guitar since a neck reset is a fact of life with most guitars, but why a mandolin?


Rob, that is a good question, I suppose it is a cary over from my guitar building days. It is really not easier then a dovetail, you still have to be very accurate cutting the mortise and tenon and drilling the holes. It does have great mechanical strength however. Of course it limits you to oval holed instruments but that is all I build. I guess it is what I am comfortable with and it works for me.

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## Jim Baker

Hmmm....... I didn't think of that possibility. Do you think I would have problems with the unsupported extension because of curvature from installing frets?

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## Nick Triesch

Many famous guitar and mandolin makers use bolts.  Weber does. Gibson and Flatiron did.  James Goodall makes some of the best guitars in the wrold with bolts.  Collings mandolins do not use bolts but use the mortise and tenon like Weber but without the bolts.  Nick

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## fatt-dad

on the matter of "using bolts."  Flatiron used screws to act as internal clamp to hold the glue while it dried.  Flatiron has a M&T glued neck joint.

To me a "bolt-on-neck" implies you remove the bolt and voila, the neck comes loose.  Flatirons and Webers are not like that.  On guitars, Martin is not like that either.

I'm not a builder, but have learned about this stuff somewhere.

f-d

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## big smiley guy

On bolt-on guitar necks that many guitar builders use the fingerboard extension is glued to the top of hte guitar but the neck itself is only attached by bolts.  It's a pretty simple procedure to removed the neck.  I'm used to using white glue for the fingerboard extension over the body since it's not an integral joint and that makes it easy to remove without having to use too much heat.

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## Jim Baker

If I glue the extension to the top I will have to make a wedge. I read somewhere that there can be problems with the extension if it's not gued down. Any comments on how it may affect sound?

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## jim simpson

I though this was interesting of Martin Guitars to try:

http://www.babiczguitars.com/martin.shtml

There were certainly examples of this concept from earlier in the century.

I think the best bolt on design would be one where the finish isn't disturbed should the neck have to be removed from the body.

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## Jim Baker

Oooh! Now that's hi tech. I'm guessing the fingerboard extension floats in an opening in the top. Not an option for me I'm afraid.

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## Kshot

Looks Great Jim!  Keep us up to date on it.

Keith

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## Dfyngravity

How about Graham McDonald? I think he uses bolt on necks pretty successfully.

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## Jim Baker

Actually some of my design ideas came from Graham's bouzouki book.

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## Graham McDonald

I think threaded inserts are the simplest way to go, but I would be a little concerned screwing them into the endgrain of small tenon you have. The ones we get here have an internal metric M6 thread and a coarse external thread. I have found a 9mm hole works well as well as 5 minute epoxy on the threads as the insert is screwed into place, but your inserts with imperial threads may be different. Trying a couple out on some scrap maple with different sized holes might be safest. One way to keep the fingerboard extension stable without gluing it to the soundboard would be to gluing a couple lengths of CF bar (like 1/8 x/1/4") into the neck either side of the truss rod so it extends a couple of inches from the heel (towards the nut) and along most of the length of the fingerboard over the body. Matching slots can be routed or chiseled into the soundboard and neckblock

I have found it easier to fit the neck before gluing the back on. You can mark the position of where to drill the holes for the inserts with a bradpoint bit without having to work through the soundhole.  Of course, if you glue the back before the soundboard, that's not going to be much help.  :Smile: 

Looks good!

cheers

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## Jim Baker

Hmmm.......thanks Graham. I'm able to reach through the sound hole with a brad drill and mark the heel. I think I should be o.k.. The tenon is 5/8" wide. If need be I can recess the insert further in. I believe the insert from McMaster Carr is 3/8" diameter. 
Next time I'll think about this ahead. 
Carbon fiber..... I just ordered my cf neck stiffener from Stewmac.  Oh well, next time I'll think about this ahead. It sure would be nice not to have to glue down the extension.  :Frown:

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## Rob Grant

Nice work Jim. With that particular classic style body and neck, I can see a definite advantage to the bolt on neck.

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## dunwell

I have been using a rod type anchor vertically in the heel for some time now. This has the advantage that it won't split out the heel wood like the inserts do and if it ever strips it can be pulled and replaced with just removing/replacing the heel cap. On a mandolin you wouldn't even have to do that what with the button. I make the vertical rod out of T-6 aluminum or brass and dust them with powdered graphite so that it won't gall with the furniture bolts. You can see an example of this on my web sit. Go to 
http://dunwellguitar.com/
click on the Luthier Links and then on "Let's Build A Bouzouki" and follow the links to page-4 down near the bottom of the page. Similar photos in the "Let's Build A Guitar" pages. The rod is flatted on one side to help start the holes and then cross drilled to match the bolt threads. It slips in place and is snug enough that it doesn't move around once it is placed. The bottom end is drilled and tapped for 10/32 so you can screw in a bolt to pull it if needs be.

Alan D.

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## Jim Baker

Wow! Thanks Alan. You got me thinking again. I like the idea of using aluminum. Since I am using 2 bolts I can make a rod full length with 2 threaded holes without adding so much weight. I wasn't going to add a heel cap, but now I think it might set off the walnut binding. If I make the heel cap to match the depth of the binding it should look o.k.

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## Joe Mendel

I use the threaded inserts w/o glue on my octaves & have had no problems to date. I don't use a narrow tenon, though, the natural taper of the neck is my tenon. My fingerboards float above the top.

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## 8ch(pl)

Nice work Joe.

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## j. condino

I've been patiently lurking, watching this thread for a bit....

I'll second it-that looks nice and clean Joe.

I've probably built 250+ instruments using bolt on necks- my own, for the Breedlove  factory, and a couple of dozen variations with students over the years. I've used them on mandolins- all the Breedloves are a simple bolt on that you can detatch in about 10 seconds with no glue or extra; my own variation on that idea looks just like a traditional heel joint, but it is oh so sneaky and clean ( no longer in use) ; I work on an amazing variety of bolt on guitar designs over at Dream Guitars ( www.dreamguitars.com) and I also use a bolt on system for the detachable neck on my fully carved double basses, and I do retrofit conversions on old Kay basses with a removable bolt on neck system.....blah, blah, blah....you get the idea....

From all of these, my feeling is that a tenon is not needed if you use a bolt on system to its full advantage. The tenon just seems to get in the way and makes changing the neck angle more work than is necessary; a leftover vestige from glued in neck origins. You also don't need to use a 1/4 -20 bolt or insert on a mandolin- it is a bit overkill- try something about 1/3 less. The MSC catalog sells long handled allen drivers that are about 14" long- that allows you to screw in the bolts via the endpin hole and not need to worry about odd soundhole configurations or being able to gain access to the inside of the instrument. 

Generally when I'm prototyping a new body design, especially for a larger instrument, I'll regularly use a bolt on neck design, then after the kinks are worked out,  I'm back to the dovetail dogma. For all of the work that it can take a small builder to properly integrat a bolt on system, I prefer and reccommend a traditional dovetail. In a production environment where 15 different people all work on the body and neck geometry, the bolt on is fast and easier to get out the door, but I've also seen a lot of broken heels from improper repairs and a trashcan full of broken neck parts from workers trying to keep up the production speed. Do you know what it is like trying to build 2 mandolins a day, every day, before lunch??? I do, and it is not something I ever want to return to....

j.
www.condino.com

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## big smiley guy

When I have used the inserts I have put a maple dowel in a mahogany neck heel to add strength and give the thread something more substatial to hold on to but it may not be necessary in a maple neck.  The dowel is glued in with Titebond and the inserts never need to be glued.

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## Charles E.

Well I for one have learned alot from this discussion. I like my system but I will look at it with fresh eyes and see if I can make it easier and faster.

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## Jim Baker

I'm a bit surprised to find that big leaf maple is much less dense than hard maple. I'm leaning heavily toward the barrel nut idea. A little harder to install but it give me a warm and fuzzy feeling.

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## smsuryan

Becoming proficient at making bolt on necks could open up a whole new world for your builds....replacement necks for bodies, just like a banjo or a telecaster...

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## Jim Baker

I've been thinking about the possiblity of interchangeable necks. O.M., Mandola, Bouzouki 

Crazy?

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## Joe Mendel

It makes neck resets almost a no brainer, too! I haven't had to do that yet with this joint.

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## j. condino

I did two neck resets last month: A Taylor guitar with a bolt on neck design that took about an hour start to finish and a 1930 Martin with a traditional glued in dovetail that was on one workbench for about a week ( I could have moved faster with it, but after steaming the joint, I like to let it dry out for awhile before putting everything back together) ....

j.
www.condino.com

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## Jim Baker

For anyone interested here is what I did. I used a piece of aluminum rod threaded in two places. I drilled from the heel for the rod. I think it will be just peachy.

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## Rob Gerety

Bourgeois Guitars have bolt on necks. I was a little skeptical.  But I have owned one for a long while now and I am convinced it is the way to go if it is done well - at least for guitars. 

Kay (I think) built these funky looking guitars years ago - maybe in the 30s? - that had an adjustable neck joint with a radius so you could very quickly and easily adjust the neck angle.  I had one for a few years.

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## Luthier

I love them.  Bottom line.  If the sound and tone are not affected, go for it.  Wood and glue and strings do not always gaurantee that the instrument (especially the neck) will never need to be worked on or fixed and posibly replaced.  It just makes sense.  I have taken the body of my Octave kits and I have been able to replace necks with different scale lengths.  Its pretty cool.  I even have a dulcimer neck I retrofitted to one of the Octave bodies.
Don

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## KenR

Anyone interested in the bolt-on/m&T/dovetail issue should check Sylvan Well's website.  www.wellsguitars.com  His double tenon joint with no glue at all allows for quick and easy resets and truss rod repairs with no damage to the finish around the fretboard extension.  Not sure if it's applicable to mandos however.  -  Ken

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## Jim Baker

Here's a picture of the joint assembled. I modified the angle to 3° from 2.5°. At this point I'm tempted to glue down the finger board extension. I've made a filler wedge from the same spruce as the top. Just can't see why I'd want to remove the neck any time soon. (If I get it right)

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## dunwell

> For anyone interested here is what I did. I used a piece of aluminum rod threaded in two places. I drilled from the heel for the rod. I think it will be just peachy.


Heh, heh, them photos look familiar!! Nice job Jim. Remember that you can also use furniture bolts instead of the all-thread rod. That works nicely for cases where you don't have a round sound hole to reach through. In that case you put in the furniture bolts from the body side and slip on some capture washers over the threaded ends so that they can't fall back into the body. Then use the long allen wrench through the end pin for tightening. Your final product looks very clean!!

Laters,
Alan D.

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## Mario Proulx

*  Bourgeois Guitars have bolt on necks. I was a little skeptical. But I have owned one for a long while now and I am convinced it is the way to go if it is done well - at least for guitars.* 

So do Collings, Huss&Dalton, Taylor, myself, as well as many, many other mid to high end guitar builders. In fact, I'd venture that there are more bolt on necks on mid to hjgh end guitars these days than dovetails. There's no tone or power penalty(I built a year's worth of guitars with dovetailed necks some time back to see if they're be better or worse than those previous and those after, and there was no perceptible difference at all, not when new, not today), but there's a definite advantage when it comes time to repair or adjust. We can reset a neck in minutes without risking damage with heat and steam, even on those that still glue the fretboard down to the top(myself, Collings, etc..). Mandolins don't need neck resets nearly as soon or as often, if at all, as guitars, due to their stiffer build(smaller spans, shorter ribs/sides), and the adjustable bridge allows a lot of adjustment room, so the advantage here is more or less moot. I can't think of a disadvantage, though, other than buyer resistance(which we've finally overcome with guitars).

A little side note: on a guitar, bolt on necks actually take more time to build and install than a dovetail neck, especially in a factory setting. You'll not find a bolt on neck on any inexpensive Asian guitar for this reason.

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## Jim Baker

Thanks everyone.  Another question: I received my carbon fiber today for the neck stiffener. The plan was to insall a piece 3/16" x 1/2" deep. I could only get .200" x 1/4" from stewmac. I am planning to stack the two pieces. 

Will the two pieces be as stiff as one solid piece? Should use a special glue to cement the two piece together before installing" It seems pretty strong, but maybe not as stiff as steel.

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## Jim Baker

Hi again. I've installed the fretboard and added a wedge under the extension. I plan to string it up and play it in the white and then I'll decide if I should glue down the extension.

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## big smiley guy

It's looking pretty good - I hope to build an Octave in the not too distant future - once I've finished a few of my other projects.

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## whyner

Hello Jim Baker:

Any updates?  I went scrounging around the woodpile to see what I could come up with for an OM because of this thread!

Steve
Oregon

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## Jim Baker

Steve, I didn't end up glueing the extension down. I strung it up and played it for a couple months and then decided to finish it. I'm still working on that.
As for the bolt on neck, it works fine. I plan to leave the neck unglued so that I can possibly interchange it at some point if I wish.

My biggest mistake with the neck was using carbon fibre as a stiffener. I ended up taking it apart and adding 1/8" steel bar on eithe side. It added a lot of mass.

Next time I will try a truss rod.

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## Vladimir Seleznev

> So do Collings, Huss&Dalton, Taylor, myself, as well as many, many other mid to high end guitar builders. In fact, I'd venture that there are more bolt on necks on mid to hjgh end guitars these days than dovetails. There's no tone or power penalty(I built a year's worth of guitars with dovetailed necks some time back to see if they're be better or worse than those previous and those after, and there was no perceptible difference at all, not when new, not today), but there's a definite advantage when it comes time to repair or adjust. We can reset a neck in minutes without risking damage with heat and steam, even on those that still glue the fretboard down to the top(myself, Collings, etc..). Mandolins don't need neck resets nearly as soon or as often, if at all, as guitars, due to their stiffer build(smaller spans, shorter ribs/sides), and the adjustable bridge allows a lot of adjustment room, so the advantage here is more or less moot. I can't think of a disadvantage, though, other than buyer resistance(which we've finally overcome with guitars).
> 
> A little side note: on a guitar, bolt on necks actually take more time to build and install than a dovetail neck, especially in a factory setting. You'll not find a bolt on neck on any inexpensive Asian guitar for this reason.


Despite discussion is over I would like to disagree that glueing is cheaper. I depends on many factors... in Russia, f.e. guitar with traditional (since 19th century) Russian-7string-guitar one-bolt joint (it is like Key joint shown several posts earlier) significantly cheaper than any asian guitar. Mainly because setup of one-bolt joint is a problem of a customer  :Smile:

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