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I’ll be using a dovetail on my next guitar and want to crowdsource some details. I’m hoping to see if there are any standards here, or if everyone kind of does their own thing with it.

How wide and deep are your neck blocks when using a dovetail?

How deep is the dovetail tenon itself?

How deep is the pocket/mortis? I remember discussion that the pocket is usually a bit deeper to create some space for glue and steamer needles.

Gratzie.




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Here is a good guide:

https://www.stewmac.com/How-To/Online_R ... tions.html

Note that they recommend making the pocket 3/4” deep horizontally and the end of the neck that goes in the pocket 5/8” long, leaving a 1/8” gap. You will want to make the end of the neck vertically a little shorter than the pocket too, so it doesn’t bottom out during fitting.

I hesitate to use the terms mortise and tenon; I’m not sure they apply when discussing a dovetail joint.

Get on YouTube and watch ALL of John Hall’s excellent videos on dovetail fitting. Lots of great info there.

Thanks, Don.

I agree re. The terminology, but tail and pin doesn’t seem quite right, either. I wanted to use language that would hopefully result in readers understanding what I’m asking.


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Is there a particular reason (aside from self-flagellation) that OP wants to willfully and with intent, use a dovetail? I think those things are fashion statements that high-end guitar manufacturers set up to justify their prices. They sure don't contribute to acoustic performance in any empirical way. A given guitar may sound good and have a dovetail, but there's no way to ascribe the acoustics to the dovetail. Ask Collings. And Dana Bourgeois.

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Peter Havriluk

Some people just like the tradition of dovetail joinery. I don't use them anymore myself but I appreciate them. I still actually do use one on mandolins and in that case I make a simple sliding dovetail joint.

Yes definitely keep some space behind the tail in the pockt for steaming the joint.

A well made dovetail joint accomplishes the work as well as any other joint and without mechanical fasteners. It allows the maker to exercise a little skill in the process. It is one of several traditional methods of joinery which the repairman should be familiar with.
I usually use a bolt on design for joining the neck to body (because I'm lazy) but I often use a modified bridle joint (bird's beak) to join the peghead to the neck shaft (because they are fun to make). Different strokes for different folks.

Never have I known someone who sees me so transparently.

That or (1) it's a hardwareless joint; and (2) might actually take less time than a mortis & tenon. I don't know. That's why I want to try one. John's dovetail series is extremely persuasive.

Everything I know about dovetails I learned from John and his videos. I still use them whenever I can't get into the guitar (which means an archtop or hollow body) but I now do bolt ons for everything with a hole in the top. I did break down and buy the StewMac templates and built a body and neck holder, which gives me a much better chance of the neck fitting the body.

The case for a dovetail, other than masochism:
A well fitted dovetail holds the neck on just as well as a bolt-on, and definitely better than a loose bolt-on.
A well fitted dovetail adds less weight to the guitar than a bolt-on.
A well fitted dovetail can be built in such a manner as to facilitate easier resetting of the neck angle, once it is needed.
A well built guitar should only need a neck reset maybe once or twice in a guitar’s lifetime.
A bolt-on may be easier for the builder, but other than minimizing the cost of a neck reset (which should only be needed once or twice in a guitar’s lifetime), it provides no benefit to the owner.
There are people who appreciate the traditional aspect of the joint.

Nothing against bolt-ons; they are fine. But so are dovetails.

I like your your approach to this, Mr. Orr - master both dovetail and bolt-on..more tools in the toolbox. If nothing else, you'll have first-hand knowledge of both approaches to inform any critique offered in any future dovetail versus bolt-on threads.

When I did my first reset here, I had nightmares about the job for the week leading up to the arrival of the instrument. I imagined the worst - I would somehow screw up the job so badly that we'd have to convert it to a bolt-on, or worse yet, return it to the owner in pieces with a sympathy card and a gift certificate to Chili's.

We got the neck off and I was stunned - shims! We get to use shims? Seriously? How often do we get a near-infinite number of tries at some supposed precision fitting task? I thought the job would require some unobtainable level of precision and accuracy...my stomach unclenched and I had a nice day after that.

Shims? Shims!

From that point on, I realized that the task was the same as fitting any other full-blind neck joint...get the neck at the right angle and alignment, get a decent fit on the bits that hold things together, keep any glue lines as thin as possible, and all the ugliness gets nicely buried under the pretty parts. When I did dovetail neck fabrication for scale length changes on archtops and for Gibson neck replacements, it became even more obvious that there was little in the way of precision needed in fabrication - get it reasonably close and the rest of the job is done with sanding blocks, files and - I'll mention it again - shims!

Summary: bored, semi-skilled factory workers have done dovetail joint fabrication, fitting, and assembly for centuries - you've got this!

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For the times they are a changin'

- Bob Dylan

Still remember my Instructor on the course saying who on earth would want to use such an obscenely complicated joint to construct a guitar when these is a simple alternative.... Just reminiscing....
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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I wouldn't use anything but a dovetail.
In 20 years of doing guitar shows I have often heard , yeah nice but its a bolt on. Not to say there is anything wrong with them but depending on your clientele that is what they want. Also if you never learn how to work one you loose a lot of work doing resets. It doesn't take long to master them.
One fact is the any good neck joint will be fine tonally but the know weakness of bolt ons is loose connections so you have to be able to retighten them . Martin stopped using them all together and now they use the sliding dovetail tenon. If you do use them do like taylor and make them with 2 bolts.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I don't know anyone that wants a bolt on. They're OK by me but if I want a chance at selling, I'm not going to mention bolts. I mentioned it to my wife once and she gave me that look and said no, don't do it. She doesn't know poop about construction but has idea about it like every other guitarist I know.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Well I have to say that for all the repairs that come through my shop, I don't really see loose bolt-on necks. Well, except for the fenders that roll in where people have clearly removed them (just look at screws and the story is obvious), and the owners don't know how to torque a fastener. I'll ignore the glued in Martin necks with a bolt.

Automobiles - we all drive them. Last I checked, my cars have zero dovetails. I can't recall teh last time I took my automobile in to have the mechanic retighten all the threaded fasteners. It's just not a problem if installation is correct. If it is an incorrect bolt-on installation - then what's the equivalent poor dovetail installation - ill fitted packed with glue that loosens over time. We can make the argument that a poorly installed dovetail would suffer a similar issue as an incorrectly fastened bolt-on - that is a loosening neck Guess which one I'd rather repair. Especially those that use Titebond in a dovetail - blech.

I agree that a working knowledge of the dovetail is especially good for the repair person. I also agree with John's observation that with a bit of work, one comes to understand it fairly quickly.

That said for those making the case that craftsmanship quality is a differentiator for their dovetails, I am most certain that you all fit your dovetails like any self-respecting cabinetmaker would - without shims.

Automobiles have no place in this debate, that's steel to steel with little compression over time. I'm sure the goal is to fit without shims but this is a far more difficult joint than a cabinet dovetail.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Build it like you want, both joints are just fine. I used to do bolt ons but since I've learned to be very comfortable with dovetails then I do dovetails, I don't think they're that difficult and I like not having any hardware in the neck joint.

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Steve Smith
"Music is what feelings sound like"

"Automobiles have zero dovetails"

And airplanes are held together with glue

Whatever system you use is the one you will feel most comfortable with in the long run. I use a dovetail. Used a bolt-on for the first 2. I like knowing that a good joint will stay on it's own, in the right place, during trial assembly and disassembly and I like lighter weight guitars. Most of all I use one because the people that helped me in the beginning all used dovetails.

If there is compression of a dovetail over time, I suspect the primary concern will be just how we managed to apply 6,000-6,500 psi compressive load on that poor guitar neck (that's something like 15K-20K pounds!).

As to exposed cabinet dovetails, the standard is a near-perfect fit without shims or filler for what might be a dozen sets of dovetails in a three drawer chest plus the exposed casework, plus interior casework dovetails which may not show, but must be well-fitted and sound. Call that something like 100 near-perfect, gapless, dovetails. A guitar has a single hidden, sliding, tapered dovetail which only needs to be milled to within perhaps a 1/32" of nominal dimensions, then shimmed to a good fit.

It seems like we over-think the dovetail and make far too much out of what is a routine task for repair people and builders accustomed to the job...it is just not that big a deal.

_________________
For the times they are a changin'

- Bob Dylan

I'm enjoying the back and forth, but for practical matters, it sounds like a 3/4" deep pocket and 5/8" tenon. Does 3"x1.5" sound good for the neck block?

The neckblock on the one I'm building right now is 2 1/8" x 1 3/8". Birch ply on top butts up to the UTB. Max width at top of my dovetails is about 1 1/2"

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Steve Smith
"Music is what feelings sound like"

I believe the Martin bolt-on guitar neck joint design was in fact a glued mortise-and-tenon - if memory serves, the bolt held the bits together while the glue dried, and was not a structural part of the joint. In any case, it is not at all like the Collings, Bourgeous, Taylor, or other successful bolt-on designs with which i am familiar.

Re: customer preference - we've seen few that express a distinct preference, but can build to suit. If a professional builder cannot build to suit, there is always one than will. Those at ease with multiple neck joints seem to find both virtue and vice in any design.

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For the times they are a changin'

- Bob Dylan

Woodie, those compression numbers are a lot more than I would have guessed. Don't the 6 strings only pull about 150 pounds? I guess the variable would be the surface area you are calculating this over.

There is only a debate for people that don't really know much about this subject. Both systems work just fine.

As for automobiles you simply missed the point. Metals expand and contract. And unlike a guitar, undergo many many hundreds of degrees of temperature difference. If threaded fasteners can work there, they can hold on to your measly guitar neck. I thought that might have been obviously understood, but I was wrong so I'll spell it out.

I took the original mention of compression to apply to the fibers of the block being compressed under the bolt head. As the wood expands and contracts there is a concern that the bolt could become looser or tighter in given conditions. The occasional snugging of the bolts would take care of this, but I could see people selling their guitars not wanting customers to have to do that.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

~250+ built and sold with bolt on butt joint, one or two loose inquiries as to neck joint construction. Doesn't seem to be a barrier to sale. Anyone who would refuse a guitar due to the type of neck joint probably isn't the right client for me anyway...

Anyway...

Neck block 3" wide, 1 3/8" deep, and as tall as the guitar orders.

Dovetail made with 14* bit

Width at top ~ 1 3/4"
Width at bottom before roundover ~ 3/4"
Length of dovetail ~ 3"
Depth of dovetail ~ 1/2" with mortise being ~ 5/8"

The important thing is to make sure the gap between tenon and mortise falls under the first fret in the body so that when the time comes for a reset, the fixer can pull the fret, shove in the steamer needle and get the steam in the gap.

Of course it's possible to do the job without shims, but it's more likely that you will need one. If you need to change the neck angle even a tiny little bit, you will create a gap in the precious 'wood to wood contact', so cherished by dovetail merchants, that will require a shim.

For me, neck fitting is always done in two stages. First in rough construction, and then right before committing the neck to glue and giving it it's permanent residence. Very rare IMO to not need at least a tiny nudge this way or that way to get the angle exactly right. Depends on how fussy you are about the exact angle.

And once it does get its most likely future eventual reset to bring the angle back...flossing the cheeks will open a gap in the joint that will require a shim to close, so...shim shimminy shim shim, shim shim, for you!

Stew Mac sells acrylic templates that comes with plans for fairly easy to build jigs. If you were local I'd offer to dig mine out of the garage for you to use, but alas, such is not the case.

In any event, don't be intimidated for as Woodie says, it ain't no big thing...