Official Luthiers Forum!

Two great perspectives from John and Bryan.

Something that can be missing too is the urging of a client to want to buy an "early" guitar from a builder etc. We usually don't hear either about how little someone may have paid for a not-ready-for-prime-time guitar.

OTOH if you don't want your name on it don't sell it or let it out of your shop even as a gift.... I gifted guitars and didn't sell any of the first dozen or so and I needed in my own mind to be capable of any future service before I accepted money for mine.

But that's not why I'm here because this is America.... where Loofiers (spelling attribution to The Padma) are free to do whatever we want.

My sincere hope is that some of these things that are being mentioned by the contributors here will improve someone's guitar, experience and maybe in a small way the reputation of the entire idea of buying a hand made instrument from an largely unknown builder.

I'll stress that we hear lots of horror stories and see some really bad work from time to time with the Luthier guitars that folks bring us but then again no one ever visits my friend and Doc unless something is not right....

I'm going to start another thread on the Positive Influence of Luthier Built Instruments out of fairness AND more importantly there has been a positive influence on the entire industry by the small Luthiers.

I was reading in this thread that some of you think it is a good idea to leave a gap at the back of a neck dovetail joint for ease in resetting the neck. That is a terrible idea in my opinion. If you leave a gap at the back of your dovetail joint you are almost guaranteed that the joint will work loose. Sure, it will be easier to repair, but you wouldn't need to repair it if you made a joint that was in full contact all around. You would never make a dovetail joint with a gap in any other context so why would you do it on a guitar. If you made a drawer like that, it would fall apart within a year.

Daniel—

If you don’t trust me (and really, why should you?), maybe you will trust StewMac. Here is a quote from their website instructions for cutting a dovetail using their templates:

“The neck tenon is usually 5/8" long, and the body mortise is generally 3/4" deep, leaving a 1/8" gap between the end of the tenon and the bottom of the mortise joint. This gap is useful for final fitting and for steaming the neck loose if future re-setting should become necessary.”

Keep in mind that this type of dovetail is different from dovetails on drawers. A guitar neck dovetail is a sliding, tapered, blind dovetail. Also keep in mind that it was the traditional joint of choice for steel string guitars up until the last few decades. This is how it is done.

Oh, and the repairs are usually not to fix a loose dovetail. It is usually to tilt the neck back a bit, which is needed to make the guitar playable again, after the top and the rest of the body deform over time.

Not only is the gap there to aid final fitting, neck removal and resetting, it is needed to allow the sliding dovetail to seat fully. If the back of the joint (end grain of the dovetail) hits the heel block as it slides down into position it will stop the dovetail from tightening properly.

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Bryan Bear PMoMC

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

Also, there's not a lot of call to reset a drawer in its later years.

Leaving a gap in the back of a dovetail is a very good idea and necessary to permit the steam that we apply to soften the glue to migrate to the "intended........." gluing surfaces. I say intended gluing surfaces because the heel cheeks were never intended to be glued to the body but alas... glue gets in there at times too sadly but no biggie.

Daniel not to be unkind but you were the one who originally made a comment that you didn't care much for what a repair person needs to do in terms of extra effort, risk, expense to the client, etc. Your comment was why I started this thread by the way, thanks for the idea. My hope is that you will see that there is value for YOU in doing serviceable work in so much as it increases your value proposition to your clients.

Properly fit dovetails are ideally suited for how a neck needs to be hanging off a guitar body with no movement beyond the unintended but should be expected distortion in the box shoulders leading of course to the eventual neck reset.

As such neck joints regardless of if it's a dovetail or bolt-on etc. need to be serviceable.

The process of fitting, chalking, removing excess material, refitting, observing, removing excess material until you have just that right fit with a tonk to seat it firmly is a beautiful thing. The joint has no need for any metal hardware, pretty much couples the neck to the body as well as you would ever want short of a neck through design and has stood the test of time. It's also survived Pete Townshend.... but not John Belushi.

Anyway that space is referred to in the trade as the "pocket" and it's necessary, beneficial, advisable, and a dang good idea too.

Continuing to beat this here dead horse: the function of pins and tails in the dovetails for drawers is very different from the function of the tapered, sliding, blind dovetail that holds a guitar neck to a guitar body. They share a name and a trapezoidal shape, but otherwise do different things in different ways. Pins and tails on drawer dovetails are meant to fit together perfectly, with no gaps showing. On a guitar neck, the two parts are really more like interlocking wedges that pinch each other with increasing applied pressure, until they can’t pinch any harder and they are stuck together. Here’s the important part, which Bryan emphasized: without that gap, the parts will stop interlocking BEFORE they lock together as tightly as possible. That gap is critical to the process of making the joint as tight as possible. Plus, why eliminate the gap? It doesn’t show. Are you eliminating it in the name of increasing gluing surface? That is not a good trade off. This type of dovetail is a mechanical joint. The glue is nearly superfluous. And in any event, no great strength comes from gluing the end grain of the neck to the inside of the pocket. The glue on the wedged surfaces is doing the job, to the extent the glue helps in this joint.

I notice that Daniel is new to the OLF. A suggestion: when you are new, questions are awesome, and people here are really interested in answering questions. Challenging orthodoxy is often a good thing, too. It is good to challenge assumptions. But there are a whole lot of ways in which building acoustic guitars is different from other types of woodworking. If you state opinions that are informed by general woodworking knowledge, as opposed to knowledge gained from actually building acoustic guitars, and if the tone of those opinions is “you guys are doing it wrong,” you are going to get some pushback. Maybe you can explore your questions about how acoustic guitars have historically been built, and how they are built today, without telling folks (folks who are actually building acoustic guitars) that they are doing it wrong. I think you will enjoy the discussion more that way.

Actually there is, as anyone who fools with restoring antiques would know. Like many things made of wood there are "wear surfaces" that need to be adjusted and sometimes renewed.
As Don mentioned, guitarmaking is a type of woodworking where many of the things we do are "wrong" from a general woodworking perspective. Using unsupported "veneers" with crossgrain glued braces being one of the worst. We build in ways designed to ameliorate our woodworking transgressions, but often are not entirely successful over the long haul. So things like replaceable fretboards (wear surface) and a neck joint that can be disassembled (to account for eventual wood deformation) are a good idea. Having a soundhole you can put your hand in to do repairs inside a box that isn't made to come apart, although not always done is also a good idea. Guitars are built on the edge of structural failure, so making provisions for repair is prudent.

Most woodworking lore and good practices transfer to instrument construction with little modification, but the notion that joints must be tightly fitted on all surfaces is not always applicable. A sliding dovetail is a different animal versus the through variety, and when fitted, what keeps the joint together and square are the shoulders of the tailed component in contact with the face of the socketed component...those shoulders (or shoulder, in a half-dovetail sliding joint) keep things together as long as the tail and socket combine to exert a tensile force on the neck to keep things seated. The bottom of the tail socket does not contribute to the joint's strength, but may interfere with the seating of the joint if there is close contact with the back of the tail and socket before the joint is fully seated. When used in the neck joint of a guitar, there is every expectation that the sliding dovetail joint must be disassembled to permit trimming of the cheeks and shimming of the tail to reestablish the correct geometric relationship between body and neck.

Resetting a neck because of a loose dovetail is a very rare event - nearly all we have seen have been due to what may be the builder's lack of knowledge concerning how the joint works or sloppy construction practices in factories. The most common failure modes we see are:

- Poor fit of the tail in the socket, which allows the shoulders to move away from the body at the heel, and

- Lack of close contact between the shoulders and body when the tail is seated, allowing the joint to work (the Norlin-years Gibson practice of using filler to close the gap between the shoulder and body and slopping glue into the joint to keep things together long enough for the guitar to sell is an example of this fault)

Leaving a gap at the back of the tail is desirable both in terms of ease of fitting and assembly of the joint (e.g., avoiding jams during assembly) and for eventual necessary disassembly as a consequence of changing body geometry. Further, there is no contribution to either strength or squareness from the back surface of the socket or the corresponding surface of the tail...the shoulders already register the neck on the body at correct angle and alignment, and the dovetail itself contributes the tensile locking force. The reason that the joint requires any glue at all is for shock and RH cycling resistance and possible failure of the fretboard extension joint. Finally, for those of us that have fitted a few dovetails, contact between the tail and the back of the socket makes fitting far more difficult, in addition to the already mentioned issues with service.

Builders: if using a dovetail joint for the neck, please, please, PLEASE 1) leave an adequate gap at the back of the joint, 2) keep that gap aligned if possible with the first fret inside the perimeter of the body (e.g., the 15th on a 14 fret-to-body neck; a too-short or too-long tail makes for either a weak joint or difficult-to-disassemble one, respectively), 3) properly fit things before glue-up (no filler!), then 4) glue with just the minimum amount of 192g or lower gram strength hot hide glue necessary, applied only to the mating faces of the tail and socket.

In summary, luthiery is far more than just applied woodworking or finishing, and instruments have a whole set of additional use and maintainability/serviceability requirements to satisfy beyond what we might see for a piece of furniture. Some woodworking wisdom is simply not applicable (e.g., cross-grain construction is an anathema in cabinetmaking and an absolute certainty in most instruments), while certain constructions such as a dovetailed neck joint have additional design considerations which generate variations or outright departures from what cabinetmakers might find acceptable.

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For the times they are a changin'

- Bob Dylan

Well, I'm not new to this, if that's the impression you get. I don't make guitars for a living but I have been building them since I was 15 and I'm 55 now. I make furniture for a living, so I know a lot about how wood behaves. Here's one of my recent guitars that I designed and made.

Excellent post Woodie, thank you for posting it.

My shop does Martin warranty repair work and recently in the last two years or so there has been a change in how Martin views neck resets.

It used to be that Martin's warranty would cover neck resets for the original, registered owner with no time limit. We reset guitars that were sold new 50 years ago and Martin would cover it.

Personally I always thought that this was nuts and a revenue recognition nightmare for the accountants at Martin.

About two years Ago Martin changed the policy to cover a neck reset for the registered original owner provided that there is a visible separation of the heel from the body calling it a defect in workmanship. We completely agreed with Martin's logic and I'll add if an acoustic guitar won't have a neck reset viewed as a warranty issue, and it shouldn't except if there is a visible gap then a neck reset should be considered normal maintenance that just may need to be done someday.

Dave and I have always believed that neck resets should be considered normal maintenance (sands a clearly defective joint...) and not covered under warranty.

With all of this said and the trend for Martin repair people being to now see the very need for a neck reset as not a defect but normal maintenance that gap behind the dovetail aligned with the first body fret is even more important. Neck joints, any of them should be serviceable if there is any possibility that the neck will ever need to be reset.

FYI if you're wondering why Hesh here is rooting for Martin to restrict warranty coverage on neck resets over what they generously did in the past it's my wish that a great company like Martin be around to play for many years to come. Having that potential liability of a $500+ repair out there for every production instrument one produces is a nightmare in many respects and could in my view eventually sink a company. That's a lot of liability.

Anyway regarding Woodie's comments regarding woodworking norms and Lutherie it's been our experience that if one is a top shelf woodworker they also have to be willing to view Lutherie as application specific. Our friend Link Van Cleave who apprenticed with us for a couple of summers is one of the top woodworking folks around. He studied with Jim Krenov and later apprenticed with him and then was asked to teach at the Redwood school. Link also had his own woodworking TV show on the left coast. He'll be the first to admit that some things in woodworking don't translate well to Lutherie. Fortunately Link is a player too and ultimately views guitars as tools for musicians and that will serve him very well.

My impression was that you may have been new to the use of dovetails in acoustic neck joints, or perhaps acoustic guitar construction, rather than more generally new to luthiery. Given the purpose of the thread was to expose those focused solely on building with what repair people have to contend with, it seemed worth the discussion in case you did not have a history in repair work or with using traditional dovetails. We've had electric guitar builders in as build students, and while they tend to do a lovely job on all of the common areas between electric and acoustic construction, the acoustic-unique operations or constructions seem to be where they get the most out of their projects.

That is a lovely guitar!

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For the times they are a changin'

- Bob Dylan

That is quite a stunning looking instrument Mr Oates.

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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.

Daniel--

First, that is a beautiful electric guitar, and you should be proud of it.

Second, what I specifically said was that you are new to the OLF, which is self-evident from the number of posts you have made and when you made them.

Third, what I also implied is that you are new to building dovetail neck joints for acoustic guitars. I'm correct about that, right? If I'm correct about it, then I think this thread has a lot of useful information for you.

Fourth, I am 100% certain that you know more about general woodworking than I do, and probably more than many of the folks who participate on the OLF. It will be great to draw on that knowledge as you participate. But as I (and others) have said, there are things about building acoustic guitars that run contrary to how a great general woodworker would do it. I hope that realization happens for you in ways that do not involve a lot of trial and error, but rather can be done by relying on the experiences of others.

If I offended you with my suggestion about "cooling your jets" on opining that guitar builders are doing dovetail neck joints all wrong, I apologize.

Some thoughts:

"It's not the stuff you don't know that gets you into trouble, but the stuff you do know that's not true" Who said that?

I'm willing to cut inept builders and repair people some slack if they really don't know what they're doing. Obviously you wish they'd recognize when they're out of their depth, but they don't know what their depth is. You grit your teeth and get on with the proper fix (it it's still possible).

A friend of mine said that the restoration department at the Museum of Fine Arts starts their day with two anathemas: one against people who use wood screws to fix antiques, and the other against Titebond. A recent tread on another site about getting a dovetailed neck loose that had been glued in with polyurethane reminded me that things can be worse...

But the ones who really frost me are the shops where they do know better, and still vandalize instruments. There was one local place where they always did work based on their judgement of the value of the instrument. I could have made a good living fixing the stuff they'd 'fixed'.

They first came to my attention when I ran into an older lady at a local store with a waldlute: an early 20th century German lute guitar. The pin bridge had been lifting, and there were some cracks in the top, so she took it into the big shop down town, where they did lots of work for the Symphony. They cut out the rose from the top so they could get clamps inside for the studs. They cut off half of the bridge behind the pin holes, and stuck on a piece of wood that had nothing to do with the wood that was there. In the process they replaced her carved bone bridge pins with plastic ones, which they glued in with Elmer's glue. When she got it back most of the rose was held in with Scotch tape, and the rest was in a baggie. They charged her $85.

This was an elderly woman on a fixed income. She'd gotten the instrument when she was a young girl, and simply wanted to restore it cosmetically so that she could hang it up and reminisce. She couldn't stand to look at it when it came back, and she needed to get the money she'd spent back and be shut of it. I bought it, and later re-topped it, ending up with a nice instrument.

In another instance they removed the top from an upright bass, and rather than piece in the chips they simply sanded 1/8" off the thickness of the edge all around, using a coarse disk sander, and glued the top back on with Titebond. When a subsequent accident brought it into my shop it took me five hours to get the top off with hot acetic acid (photographer's stop bath). The sound post crack 'repair' they did required a 5"x 9" patch, and other damage to the top ended up needing over a hundred studs, to go with the complete half edge and another large patch at the upper end of the bass bar (which needed replacement). I lost money on that job, but it went out right.

I could go on. The point is that, in the end, judgement of the worth of the instrument is not your call. That waldlute was only 'worth' about $75 on the open market, but to that lady it was beyond price, even though the $85 dollar repair was a stretch for her. The bass was pretty generic (although it had a carved back), but it had a great jazz tone, despite not being much of a 'serious' instrument. Another "$200 fiddle" they messed up, which belonged to a friend of mine, turned out to be worth more like $10,000 (in the early '80s). It didn't look like much, but had been made in 1789 by a little known but respected maker.

Good instruments deserve good work; if the customer doesn't want to spend the money it's probably best to refuse the job. Sometimes it's hard to know how much work it's going to take until you get into it, and if you're disposed, as I was, to simply eat the difference rather than put out bad work, you end up not making much money. On the other end, when somebody wants a top-notch job on a cheap instrument for what ever reason, that's what you do. It's the customer's call on that end.

As much as it goes against personal experience, I’m taking your advice. This afternoon I cut a new dovetail jig. Here is my first test on a scrap of oak. Note the gap at the back of the dovetail.

Nice looking guitar Daniel,
What type of neck joint did you use?
There are some well respected instrument makers who don't build with serviceability in mind. A friend of mine bought a cittern type instrument from a well known English maker who builds the necks integral with the sides and back, rather than using a separate end block. It required a neck reset after a few years which was basically impossible to do without disassembling the body (which was also impracticable to do). The original maker refused to take on the repair, as would anyone with half a brain who wouldn't want to become involved in what has become an expensive wall hanger.
If you follow traditional practices and construction techniques, even if you don't get everything right, there is still a chance it can be made right. That is one reason novice builders are advised to follow a plan of a traditional design.

Well said Alan, I always look forward to your well written posts.

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Joe Beaver
Maker of Sawdust

Clay, it’s similar to a Gibson neck joint. Not designed to be taken apart. You can remove the fretboard to get to the joint, but that can damage the neck binding if not done carefully.

So specific ways to make an instrument more servicable...

Ok.. A few....
Bolt on necks. You pick the flavor. The deal there is that the easier and more straight forward a neck reset is - the more likely somebody will get one done in the future when it needs it rather than chopping the bridge... The good part with them is that it's obvious - it won't need exploratory surgery to find the pocket behind the neck...

Only use weird exotic glues on places where future repairs will likely have to cut it apart anyway.... For example using epoxy to glue the fretboard to the neck is probably fine. Chances are pretty good that if you have to pull the fretboard all the way off - it's going to get machined off and a new one fitted anyway... Don't use it on the bridge or the neck extension - as those will probably need a touch up in the future...

Otherwise use conventional, expected glues. I know some people rage about titebond - but it's been in commercial factory use for almost 60 years now... It's known and expected now.

Speaking of glue - clean up your mess at the correct point in the gluing process. It makes everything go 100x easier later.

Speaking of glue again - if you mess up a joint, take it apart, re-prep it, and do it over. Don't try to just slobber some extra glue into it, clamp it extra extra hard, and hope for the best.

Bridges - radius the bottom of the bridge to match the top radius. It makes everything go easier after this and it's a lot less likely to have the wings pull up.

On setups - get a set of feeler gages, string slot files, and a Stew Mac string spacing ruler. Use them to do your setup.... You probably can't eyeball a good setup.....

Another is to test your fret saw and adjust the kerf for cutting the fret slots properly *before* you cut all the slots and find out they are too narrow for the frets and cause the board to chip....

Those are a few things I can think of....

Al's point is buried in the post, and it's one worth discussion. In general I would agree, but I believe the statement is incomplete if taken as is. About 25% of the work I perform ends up being repairing messes that other repair people have performed - that is, people that get paid to repair instruments. This baffled me when I first started in this business, assuming that it was a niche craft and hence one would find cream of the crop repair people. Naivete I know. But this also means that I've gained a tremendous amount of experience with the above statement; I'd say it is not that simple.

I strive to exceed my client's expectations. If I do not believe I can do so, I decline the job or refer it out. If work is particularly specialized in a way that can materially affect the value of an instrument, I may refer the client to where the value can be maintained. For instance, I had an Olson in that needed refinish - rather than do the work, I referred the instrument owner back to Jim, and the work done under his hand would maintain the value of the instrument.

Next, clients are some times not well equipped to make trade-off decisions. I see it as part of my work to help them with trade-offs. When an instrument comes in I never quote on the spot - as I tell people, when they visit my focus is on them (the human) not the instrument (the inanimate object). I have missed things about an instrument when I review it in the face of the customer. I've had guitars come in, for instance, with a scratchy volume pot and discovered in the inspection process that a feeler gauge showed the bridge was lifting off. Having that guitar come in, charging say $30 for a volume pot repair, then having the bridge come off a week later on stage reflects on me. Exceeding expectations means I take the best responsibility for the instrument when it enters my shop and advise my client, even when they don't know to ask.

The above is said for context. Back to Al's good quote, I've done plenty of cheap repairs. A good example are the $200 chinese classical guitars that pop a bridge. No rout, epoxy glue-up might be an inexpensive $75. I'm pretty certain the guitar will stay together and it achieves the goal of an inexpensive practice instrument for a possibly budding child. That said, it is MY responsibility to decide what comes out of my shop. The judgement of a repair I'm willing to stand behind has NOTHING to do with the client's view of the instrument. Our discussion certainly has an intersection between the two, and my understanding of the client's perspective is critical. But that decision to perform the work bears my name on it. Any experienced repair person also knows that the reputation of one's work is not just with the immediate client, but with others that may play the guitar or see it. A customer is not going to convince me to do work that I can not well justify in the face of another person - that's a community reputation killer. If I'm not comfortable with producing the outcome for the client, I let them know why and offer a referral if I have one. I've had the conversation with clients, explaining that I cannot perform a repair as they desire because the issue is not that they would accept it, but that others would observe my work and conclude my reputation. I've had exactly zero clients or potential clients that have not understood. It's not an insult at all to the client. I have their best interest at heart as well as mine. I'm sure one day that streak will be broken, but knock on rosewood, not yet.

My derivation of Al's quote would be,

The point is that, in the end, judgement of the worth of the instrument is not your call, but the decision to perform the work is your call and a reflection of your reputation in the community.

AndyB:
That was the point I tried to make in the last paragraph of a too-long post. Thanks for condensing it down.

Al, I'm afraid my rambling was not much of a condensing, but thank you nonetheless!

I have seen a LOT of old guitars with loose necks. But it wasn't from the pocket behind the neck - it was just a horrible job fitting it in the first place.

The first issue there is just very poorly made dovetail and pocket. Glue won't fix a poorly fitted dovetail. I have a feeling that large number of Harmony and Kay made guitars rolled out of the factory with poorly made neck joints.

I think a common issue was also folks sticking them up in an attic or some place they would see a lot of heat. The hide glue turned to powder and the neck slides right off.