Official Luthiers Forum!

In my attempts to construct instruments of high quality and playability, I study and research lots of other guitars and literature on lutherie. Construction techniques and methods are on the top of my list of priorities. This makes me ask a few simple questions regarding the accepted, traditional methods used in guitar crafting. Understanding the dissolution of some products/glues etc..
#1: Why should or would a guitar, whether hand crafted or factory built instrument ever need to have the neck re-set? This is one of the reasons I've gone away from bolt-on necks. And when I do a bolt on I leave no room for wiggle or adjustment, tighter the better.
Instruments are designed and built to be rather fixed in their construction, the fret board extension is fastened to the body by glue or screws, the neck is seated tightly and glues in place or is bolted.
The action is predetermined and the scale does not change. I just had a man come over to my shop and inquire from me the price to reset the neck on his 4 year old Martin. One of the worst I've seen. Now I've seen some guitars that do not have a truss rod and after several years the neck just pulls up and is not correctable, that's an oversight in my opinion with regards to the way it was constructed. But nothing within my reasoning can make a good argument for why a guitar would ever need a neck reset, (unless no truss rod was used), if you're using a glue that creeps over time, like HHG than I can see this, but has anyone ever tried to use epoxy to eleviate this need. Even if the neck is reset, it often is not the same as originally constructed. At what point is the replacement of the instrument considered entirely, as with resetting comes refinishing, cracks and so on.
#2: Same philosophy, why would the bridge need to be removed and/or replaced (if the neck never moved). Given the life of some instruments, well over 100 years and still playable today, this makes me think that some of the traditional methods used in the constuction of acoustic guitar,(and others) is old school and out dated. I've read and/or gathered from early text from popular builders that such things were used or put in place to accomodate a need for "future" repairs. this could be untrue, could be fabricated or it could be something that has a bit of legitimacy.
I only bring this up as a means to understand why this is accepted or that is, when we know how something is supposed to be and the durability of some instruments is rather compromised by old school techniques it factors in to my building methods and even my warranty policies safeguarding the customer as well as myself. By doing some simple mathematical calculations I unequivocally arrive at the notion that is better to offer a replacement instrument than to offer one that needs to be repaired years from now. Refinishing and resetting a neck just to get it back to it's original form still seems a bit undue if not premeditated. Does this make any sense to anyone else?
Believe me when I say that I just would like to know from others what they think about this, or if they have ever questioned it. Is it possible to craft a guitar that would not need these repairs? Even 100 years from now? Given the products and glues available today? I'm not convinced that a guitar can not be built to withstand 100 years of playing (under proper conditions and care) that will not need a neck reset or bridge replacement. Maybe I'm wrong. Feed back needed.

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Nehemiah Covey
www.coveysacoustics.com

The simple answer is that wood moves with time and being under tension. Eventually, a neck will be stressed away from what was at one time it's normal condition. There are other factors besides time and tension such as temperature and humidity, but the two biggies are time and tension. Those same forces that cause a neck to move into a different shape are also working on the upper bout and the bridge area. The forces of the strings are trying to pull the bridge up in the back, and push it down in the front. Over time, those forces can slowly deform the top and bracing structure. The forces also put the upper bout in compression, meaning that the forces are trying to collapse the upper bout into the sound hole. In a sense, the point at where the neck joins the top is a fulcrum. It wants to pull the bottom of the heel out, while pushing the top inward. This adds stress to the rim and back as well. There's a lot going on because of that string tension!
Some old instruments that seem to be perfectly playable 100 years later may have indeed had neck resets in the past. They also may have never had anything other than light gauge strings on them. Like I said...many factors. Neck resets are inevitable. That's why some folks use bolt-on joints to facilitate an easier resetting operation.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Good arguments for the traditional method of construction Don, but I'm still not convinced.
I have 3 very old parlors built by my great-great grandfather back in the late 1800's (actually they're not mine yet) that show no need to have the necks reset or other adjustments, they are currently strung with P/B and have been so for many years. The only thing I know about their construction is a tar based glue was used in setting the neck and bridge, along with 100% egg white finishes that still looks good today. (can't wait to get ahold of them) I don't know if I have good data to back this up or not, but it just seems to me that another method could be better, based on the 3 I described. Did I just stir up a

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Nehemiah Covey
www.coveysacoustics.com

I agree with Don on all points.

Another way to look at it is that the acoustic guitar, in it' simplest form which I pretty much believe to be a traditionally built guitar, seems to evolved into what has to be close to the fewest number of functionally required parts.

Nothing lasts forever, nothing..... Not to make anyone puke but there is a real charm to owning an instrument for years and hearing it open up and change. If you have to at some point "participate" in the care and well being of your friend/guitar all the better.

There are many builders who have very good designs that are complete or partial departures from a traditionally built guitar and IMHO some of these designs will indeed eliminate the need for a neck rest - ever.

As for epoxy for bridges not a good idea also IMHO. Ovations used epoxy....... nuff said.....

Ok ...

Whats the scale length ?? How thick is the top and how are they braced, what are the bout dimensions ??? what were they strung up with initially ??? What was the original action ??? The saddle is still in its original size ??? The nut slots havent worn down requiring a new nut - changing strings and tuning over a hundred years would surely cause the slots to be too low and cause buzzing. How about fret work ???? none - then they have never really been played all that much...

Smaller guitars with shorter scale lenghths have the ability to last longer IMO - less tension, and the smaller top size resists bellying - has the guitar been at concert pitch all its life, with steel strings ( I am not entirely sure when steel strings came into being the norm) ???

The type of glue used to set the neck is irrelevant IMO, as is that for the bridge - so maybe it didnt creep, but whats that got to do with the top bellying over time - nothing. The internal bracing and top thickness are whats important there, thats what is resisting the tension of the strings.

Countless many more built from a similar timeframe or sooner have not survived without at least some work. The environment a guitar lives in over its life can also have devastating effects.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I think a lot of the neck reset is actually a side reset, where the sides near the neck have collapsed. Would that be prevented by better support there, such as a Spanish style heel-- or something else that does not easily bend over as a flat tail block does? Just a thought, and I have no expereince trying this.

Hot hide glue does not creep. It becomes brittle and hard as glass.

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"After forty-nine years of violin building, I have decided that the search for a varnish is similar to the fox hunt. The fun is in the hunt."
Jack Batts Maker and Repairer of Fine Violins

I don't know about your grandfathers's guitars, but I would guess the vast majority of vintage Martins have a neck reset at sometime in their lives. Pioneer luthier and author David Russel Young advocated butt-gluing necks with epoxy, making them virtually unremovable. He suggested that an angle problem could be corrected by re-tapering the fingerboard. Try this with a full scale Tree of Life inlay. He now makes violin bows and no longer will repair his old instruments......

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It's not the miles ahead, it's the stone in your shoe


In Markham,Virginia

Interesting debate. My twopenneth would be not to forget why guitars are made... sounds a bit simplistic, but bare with me. These instruments are made to be ....played. to create music. The fact that as builders some have become works of art and beauty and a testement to the skills of the luthier in question is actually in theory of secondary importance to the practical use of the the guitar - whoever the customer is, the use they put to it, is their choice, but the instrument has been built to perform first and foremost, otherwise why worry about tone!

As such the guitar is a compromise - better tone, less structural rigidity ... a compromise that is then subjected to years of: humidity changes, heat, gigs, sweat, beer, hard playing (in many cases) by musicians who in many cases will see this as a functional tool, not an ornament. The fact that wood as an organic product that will never stop 'drying and absorbing moisture, oxidise and eventally crumble is a sad fact of building from such materials. Surely then for many players the most important thing is being able to extend the USE of the instrument as long as possible and if that means a neck reset to make it playable sobeit? why does it need it? well many things I guess, quality of the original material and build will effect it and as builders that is one area where builders can make a difference, but when you consider all the other factors, climate, age, and how its played and stored, these are beyond the original builders control.

The presence or lack of a truss rod has nothing to do with whether a guitar needs or will ever need a neck reset. Your first post shows a lot of misconceptions about guitars and guitar repair.

I agree with Barry.

It's not the glue...as Chuck stated, HHG will not creep. That's the primary reason why we use it.

Hint...why are so many builders paying more attention to the neck block...CF rod buttressing, stiff double sides, etc.?

This is a good thread...let's keep it instructional and positive.

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JJ
Napa, CA
http://www.DonohueGuitars.com

I can understand why guitars could need neck resets and I think this is a large part of the reason that many builders have gone to bolt-on construction. Eliminating glue from the neck-heel joint makes neck resets a breeze.

I have, however, wondered why no one uses epoxy to glue bridges. (And yes Hesh, I hate Ovation too!) Isn't the epoxy stronger & less susceptible to humidity changes? The only reason I can see for not using epoxy is that there is always a possibility (no matter how remote) that the bridge will need to be re-glued or repaired and that epoxy is just too much of a pain to work with in that situation. Is that it? Or am I missing something?

As for distortion at the neck joint my thinking lately has been more towards the back than the top. I built a couple of guitars with bolt on necks and didn't attach the fingerboard extension. It stayed flat on the top and I had some CF running into the neck block a little and thought it would be OK. Looking at them a year later,the top has not caved in at all in the upper bout and the heel is still flush to the sides but there is the ski ramp loud and clear. I think it is a combination of the shear force of the top end grain (since the extension is not glued down) not helping to counteract the dome of the back flattening out and allowing the sides to distort out from their original angle. My thinking now in terms of counteracting play in the neck angle is to have a nicley curved upper bout that does not go flat, a flattened upper bout on the back, and a very stiff fingerboard (especially as it gets closer to the body join) firmly attached to the top past the neck block. All of this is strymied though by the fact that there do exist old OM's with a flattened upper bout and normal back bracing that still have a flat fingerboard. I have to admit that I don't fully understand why some do and some don't.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

Epoxy for gluing on bridges is not a favorite, or even something that I would consider because we have some very good choices such as HHG and fish glue that will not creep, provide ultra thin glue joints, and dry crystalline hard which some of us, me included, believe helps foster more efficient vibration transfer.

Mind you there are some very good epoxies out there these days that are not the borg type, rubbery stuff but nonetheless a bridge that has been well fitted, scraped prior to gluing and glued with HHG or fish glue should never come off under normal use and with ordinary care.

Although serviceability is on some of our minds not all epoxies will release with temps that are easily obtainable. 145 degrees will release HHG and fish glue should a bridge ever need to be removed or replaced.

My condolences on owning the Ovation....... And know in advance no offense intended - ever.

Good thread!

Burton,

I think you may be right on the fretboard extension not being glued down.

The upper transverse brace I think is commonly believed to help keep the top from sinking in that area due to the fretboard wanting to push the top down in that area. I think it also helps take up some of the shear force you're talking about, that force from the neckblock that pushes along the grain of the top. It seems to me that not having the fretboard extension glued down would mean less resistance to that force. Makes me think I need to keep an eye on the three keepers I've built that don't have the extension glued down.

I also think the back has a part in it too. The force exerted by the strings must at some point be taken up by the back, beginning, or perhaps ending, at the bottom of the neckblock, where it contacts the back. The back in that area prevents the neckblock from tilting up by virtue of its being glued to the back, but also by providing shear strength for the sides. If trusses are used, such as done by MacPherson and Turner and others, they would help keep the neckblock in its proper relationship to the sides. But the string forces are still trying to pull the lower bout area — the part past the end of the trusses — up and closer to the nut. The stiffness in the back would take up where the trusses leave off. Seems we could make a nearly perfectly stiff back, or use more trusses like the way a banjo pot is kept from folding up over time, or maybe something like a through-neck on an electric, but I wonder what such a stiff guitar would sound like. Seems it would have an effect on the mode that involves the whole length of the guitar. I forget what it's called. Alan C?

The way these forces work can be clearly seen if you get a chance to closely examine a guitar with severe heat damage, where just about all the structural joints have begun to let go. It's quite an education. I forget which issue it is, but American Lutherie had an article on the forces exerted by the strings on an archtop guitar. Different animal, but the forces on the instrument overall, bridge and top excepted, would seem to be similar.

Nehemiah, I wonder of those guitars might have been overbuilt a bit, hence their survival all these years, especially having steel strings on them ? Their small body size, possible shorter scale lengths, and perhaps being 12 frets to the body may have all contributed to their longevity.

Just my .02.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

Interesting responses everyone, I'd say it's easy to draw the conclusion that most are comfortable with the traditional methods of instrument construction, and I have to clarify that the creep I mentioned is not from a slow moving liquid but rather the breaking down of bonding properties from the crystalization of some adhesives. I've restored antique furniture that exhibited the same glue hardening and failure.
I don't want to turn this into an argument, I really want to know if any of you have thought about alternative methods , reinforcements, or design changes that challenge traditional thinking. CF and double sides/tops among others are good points and ideally are addressing durabilty in guitars. I've seen several custom instruments that play and sound beautifully, but after only a few months, the tops have big splits in them or the neck is said to need a re-set. Now I know we've all heard this and seen it, someone writes in that the action is bad or there is no saddle left, and the first reply is "you might need a neck re-set".
I am trying to circumvent such repairs based on the premature (IMO) repairs (not my own) I've made to some recently.
Combining certain traditional applications and products in the crafting of guitars is what I'm questioning, not whether a 40 yr old Martin needs a reset, but will mine in 40 yrs, if constructed differently. Just me thinking out loud.

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Nehemiah Covey
www.coveysacoustics.com

Guitars with fully adjustable necks(like Babicz guitars) never need neck resets-simply turn a screw (the guitar doesn't even go out of tune) and problem solved!!
Why isn't everyone using this type of "joint"?

Perhaps because he has a patent on it?

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formerly known around here as burbank
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http://www.patfosterguitars.com

Pat,
I was just using Babicz as an example. There are many types of adjustable neck joints that have been done for over 100 years. And with a little ingenuity we could all "invent" our own.
I was just trying to ililustrate the point that there is a way to solve the problem of the neck joint "creeping".

Oh, I thought you meant his design. Too bad it's patented - it's really excellent, probably the best I've seen for the player, though likely requiring some proprietary hardware. I had come up with something very similar from having used small linear bearings in circuit board manufacturing equipment years ago. But dang, he beat me to it.

But yes, we could all build with adjustable necks. I have one in the works but I'd sure like to do one that doesn't require re-tuning and doesn't impinge on his patent. For now, building with a butt joint, perhaps the simplest non-adjustable for resets.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

Ken Parker also has an adjustable neck design that doesn't go out of tune when adjusted.

Those necks are very cool. Some of them I think give some flexibility to alleviate the problem, but do not necesarily solve the problem. I do not have direct experience with the Babicz neck. I thought they were to provide the player with some adjustment in terms of playing styles and situations rather than compenstae for the instrument deforming. I suppose it really doesn't matter as long as it works!

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Burton
http://www.legeytinstruments.com
Brookline, MA.

This is a most interesting thread.

On one hand it is the desire to make instruments which sound better than factory built guitars, but there may be a trade off because they are built lighter and are more prone to the wood moving over time. On the other hand, if you build in enough strength to avoid this from movement happening, you would be overbuilding and overbracing to the point of loss of volume and tone.

I used to think that plywood guitars solved the problems, but I have seen plywood guitars that also gave way to a belly and caving in around the sound hole, so this is not the answer either.

This is a very good topic to ponder...

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Reguards,

Ken H

The Babicz joint seems unnecessary heavy in joinery and hardware:
http://www.google.com/patents?id=QUmCAAAAEBAJ&dq=Babicz+guitar
Nothing beats the Stauffer joint, of which Rick Turner's is a modernized version (Howed-Ormed…). Simple, effective and light.
Ken Parker arch-tops are incredible. His neck joint looks to be based on a fulcrum, maybe there's a rod inside the neck that hinges on the post and the setting screw stops the neck down? Anybody saw a exploded view of this joint? Looks ultra cool and minimal.
http://www.kenparkerarchtops.com/

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Interesting:

The Babicz patent specifically does NOT claim an instrument with an adjustable neck that changes the angle of the neck relative to the body. Only the vertical height.

Claim 1
"...continually adjustable means to move said neck vertically without changing the angle of said neck relative to said body..." (emphasis added)