Tone: Bolt-On vs. Set Neck

[ggunn]

Nah, I just gotta useless Masters Degree in Musical acoustics.

Misplaced decimal point Something similar happened here in London when they built the Millenium footbridge. They took ages to find out what was happening as the bridger started to violently wobble as people crossed it. The Engineers in question were called and explained there calculations and sure enough everything was fine.. A while later and after much head scratching they found out the public were to blame. Turns out that without knowing it you fall into step with others as you cross a bridge by just feeling the slightest acoustic response. Put a bunch of people on the bridge and they would set it into motion.

Much money and time later they built damping into it and all is well.

Yeah, I remember hearing that marching soldiers collapsed a few bridges (in WWI, maybe?) when they happened to hit a resonance peak while crossing them before the commanders learned to get them to break cadence and simply walk across them. And of course there was that hotel balcony (in Memphis, wasn't it?) that collapsed during a swing music party.

And there was the infamous Mars shot which augered in because two teams of engineers didn't write in the units - one team meant pounds and the other meant kilograms. Oops.

 

[muttley600]

Thing is with the Millenium footbridge was they took all the known considerations into account. What they found was not that people were marching in step but with a very slight resonance of just a footstep ahead of you on a bridge you will fall into step without knowing it. If enough people do it a standing wave was set up. Crazy we didn't know this til 2001.

I suspect there are a lot of other things we are not being told when it comes to engineering failures. Like what the hell happened to our Beagle 2 mars explorer. Word is as it was programmed by Brits. When it got lost it was too proud to ask for directions

 

[TelePaul]

Thing is with the Millenium footbridge was they took all the known considerations into account. What they found was not that people were marching in step but with a very slight resonance of just a footstep ahead of you on a bridge you will fall into step without knowing it. If enough people do it a standing wave was set up. Crazy we didn't know this til 2001.

I suspect there are a lot of other things we are not being told when it comes to engineering failures. Like what the hell happened to our Beagle 2 mars explorer. Word is as it was programmed by Brits. When it got lost it was too proud to ask for directions

Jesus Muttley, stop taking all the fun out of rocking out wud ya? I'm learning about CAPM and approximated required returns on assets but I'm not all up in your face with it! Can't I maintain my piece of shit cornflakes-box electric with clothes-pegs for tuners is better than Jimi's 1959 LP? Can I, huh??

 

[muttley600]

Jesus Muttley, stop taking all the fun out of rocking out wud ya? I'm learning about CAPM and approximated required returns on assets but I'm not all up in your face with it! Can't I maintain my piece of shit cornflakes-box electric with clothes-pegs for tuners is better than Jimi's 1959 LP? Can I, huh??

See now you've gone and lost me there Would that be something to do with why I have no money

 

[TelePaul]

See now you've gone and lost me there Would that be something to do with why I have no money

Actually, jokes aside, most of the formulae I'm learning seem to be about guaranteeing returns on investment...seems to good to be true, but I think its a contributing factor to shrewd investment. Of course, you're doing something you're passionate about for a living...I'm hating this finance stuff (though it's just one aspect of my degree).

 

[dkerwood]

I know a luthier who builds custom guitars and swears by bolt on necks. He hates having to do set neck jobbies. Why? He says that a QUALITY bolt on neck actually makes more contact with the body than does a set neck. Makes sense. No glue there to interfere with vibrations.

For what it's worth, he doesn't care much for neck thru models, either, but that's for tonal reasons.

All that aside, my Les Paul has miles more sustain than my Strat does, but we all knew that.

 

[Light]

I know a luthier who builds custom guitars and swears by bolt on necks. He hates having to do set neck jobbies. Why? He says that a QUALITY bolt on neck actually makes more contact with the body than does a set neck. Makes sense. No glue there to interfere with vibrations.

For what it's worth, he doesn't care much for neck thru models, either, but that's for tonal reasons.

All that aside, my Les Paul has miles more sustain than my Strat does, but we all knew that.

I've heard that before, but I've never played one of these guitars that made me buy it.



Light

"Cowards can never be moral."
M.K. Gandhi

 

[muttley600]

I know a luthier who builds custom guitars and swears by bolt on necks. He hates having to do set neck jobbies. Why? He says that a QUALITY bolt on neck actually makes more contact with the body than does a set neck. Makes sense. No glue there to interfere with vibrations.

For what it's worth, he doesn't care much for neck thru models, either, but that's for tonal reasons.

All that aside, my Les Paul has miles more sustain than my Strat does, but we all knew that.

Thats great if it works for his style of building and gives him the sound he's after, he's wrong about the more contact thing but I suspect he knows that. There is a better contact with a glue joint period. They are a whole lot quicker and easier to do I'll agree and esier to setup Again there is nothing wrong with a bolt on they are just different thats all.

 

[Light]

Again there is nothing wrong with a bolt on they are just different thats all.

That, of course, is the real crux of the matter. NONE of what we are talking about is "better" or "worse," just different. Everybody wants to hear different things, and it is just a matter of what you like, not what is better or worse.


Light

"Cowards can never be moral."
M.K. Gandhi

 

[TelePaul]

That, of course, is the real crux of the matter. NONE of what we are talking about is "better" or "worse," just different.

My necks are definitively 'better'. They use a super-polymer alloy to bond the molecules with a fusion laser (mounted to my arm)

 

[ggunn]

My necks are definitively 'better'. They use a super-polymer alloy to bond the molecules with a fusion laser (mounted to my arm)

Your neck is mounted to your arm? Doesn't that make it difficult to use the telephone? ;^)

 

[TelePaul]

Your neck is mounted to your arm? Doesn't that make it difficult to use the telephone? ;^)

Yeah, and swim...I drown alot.

 

[dkerwood]

Thats great if it works for his style of building and gives him the sound he's after, he's wrong about the more contact thing but I suspect he knows that. There is a better contact with a glue joint period. They are a whole lot quicker and easier to do I'll agree and esier to setup Again there is nothing wrong with a bolt on they are just different thats all.

He's wrong? How can that be?

Take two identical necks and two identical bodies. One is set in place with a layer of glue separating the neck from the body. One is set in place, neck to body, and uses bolts to hold it there tightly.

How can a glued neck, which is separated from the body by a layer of glue, have better contact than a bolted neck which has no such separation?

 

[TelePaul]

He's wrong? How can that be?

Take two identical necks and two identical bodies. One is set in place with a layer of glue separating the neck from the body. One is set in place, neck to body, and uses bolts to hold it there tightly.

How can a glued neck, which is separated from the body by a layer of glue, have better contact than a bolted neck which has no such separation?

Probably somehting to do with the waves passing through the glue easier than via bolts? I dont know. Seems odd doesn't it?

 

[muttley600]

He's wrong? How can that be?

Take two identical necks and two identical bodies. One is set in place with a layer of glue separating the neck from the body. One is set in place, neck to body, and uses bolts to hold it there tightly.

How can a glued neck, which is separated from the body by a layer of glue, have better contact than a bolted neck which has no such separation?

I'll quote myself

Anyone can deny the findings and accuse it of being "anecdotal evidence" but that dosent stop the laws of physics and mechanics from holding true. At the boundary of both joints soundwaves will experience different levels of damping or impedence, diffraction, refraction and reflection.

What that means in terms of the basic physics is that soundwaves will not pass through a clamped or friction boundary as well as they will through glued or fixed boundary. With the glues that are used for guitar making the joint is sealed and will have fewer pores or open spaces than the rest of the neck surface. And as long as the glue holds it will never move. If it does it will fail under the tension of the strings. The bond is both mechanical and chemical. You can in one way look at it as a joint using millions of little bolts rather than 2, 3 or 4 large metal bolts. With the latter the surface of the timber will inhibit the soundwaves by refracting and diffracting the sound waves as well as reflecting quite a bit as well.

With a glued joint the soundwaves pass well through the joint as long as the cured glue has a high stiffness property. Most do. Epoxy would possibly be one that wouldn't work well for that joint and is rarely if ever used for critical joints. The popular choices in instrument making are aliphatic resin glues which are the yellow Titebond type or good old fashined hide glue. Both set like glass. Some factory shops have experimented with other types.

A bolted joint also has the benifit or disadvantage of being more easily prone to moving with changes in humidity and tempreture. This can allow the guitar to withstand some extremes that a glued joint can't but can also play havoc with tuning, intonation and your setup with relatively small changes of the ambient humidity or temp. With a glued joint you can still have problems with humidity and temp changes but not as frequent but often harder to fix. This is one of the reasons Taylor switched to their shimmed and bolted neck system with their acoustics, claiming it can give you an easy fix for a setup in Hawaii or Alaska...no comment!!

I say again This does not make one type of joint better just different.

 

[muttley600]

My necks are definitively 'better'. They use a super-polymer alloy to bond the molecules with a fusion laser (mounted to my arm)

I gotta get me some of that to experiment with. How well does it glue and screw??

 

[Light]

Take two identical necks and two identical bodies. One is set in place with a layer of glue separating the neck from the body. One is set in place, neck to body, and uses bolts to hold it there tightly.

Think about it like a heat sink. Will a heat sink work better with or without a heat sink compound? It's the same thing. Glue bonds to the wood on a molecular level; and the glues most builders like to use dry quite hard, making them a very efficient material for transfer of energy. IF you use the right kinds of glue, of course. You want a glue which will cure to a very hard bond. In this reguard, hide glue is one of the best, but it is so tough to work with that it is rarely used for neck joints, though it is exceptional for top braces on an acoustic guitar, as well as other parts which are easily clamped up (bridges, for instance). Good quality wood glues are perfectly fine for most circumstances, assuming they are fresh (when they get old they can cure soft). Some epoxies also cure very hard, but the lack of reversability make them a bad choice for anything which may one day need to be repaired (neck joints, as an example).


Light

"Cowards can never be moral."
M.K. Gandhi

 

[muttley600]

Light, Good analogy Thanks.

I use a lot of hide and for neck joints. The main problems people find with it is the lack of open time and getting the stuff mixed right and keeping it fresh. The way I had it most epoxies have little in the way of sheer strength and they can creep badly as well. Heat will seperate most epoxy. Its a Bastard to clean up after tho! As matter of interest what is your main choice for stressed joints??

 

[Light]

Light, Good analogy Thanks.

I use a lot of hide and for neck joints. The main problems people find with it is the lack of open time and getting the stuff mixed right and keeping it fresh. The way I had it most epoxies have little in the way of sheer strength and they can creep badly as well. Heat will seperate most epoxy. Its a Bastard to clean up after tho! As matter of interest what is your main choice for stressed joints??

We use hide glue on every joint in repair on vintage instruments, including neck joints - though we charge a lot more for it, `cause it is such a pain in the ass. For newer instruments, we do most of our repair work with LMI's Instrument Builder's Glue, which is essentially Tightbond without the yellow color added, which makes Tightbond softer than it would otherwise be. As far as building goes, I frequently use high end epoxies (West System or System Three) for the basic joints in my neck-through guitars, including laminating the neck (a five piece laminate), gluing the body wings to the neck, and glueing the top to the body. I want to be damn sure that the joints don't fail, and these are epoxies which dry as crystal, have extremly good strength in all directions, and are rated for temperatures where glue failure is the least of my worries - I'd be much more concerned about the wood bursting into flames. I do NOT, EVER use epoxy for anything which might need repair in the future, such as gluing on the fingerboard or peghead overlays. On dad's acoustics, he uses hide glue for all the top braces and the bridge. Almost everything else is the LMI stuff, including neck joints, back braces, gluing the box together, fingerboards, etc. We use cyanoacrylate for gluing on nuts, gluing down fret ends, purfling, and for sealing some kinds of wood (Cocobolo bleads like a stuck pig if you don't seal it, and cyanoacrylate seems to help). Cyanoacrylate also works well to fill some dips in a finish, if you fill them early enough in the process. Epoxy is also good for bigger finish dips - again, if you do it early in the process.

I think that about covers it.


Light

"Cowards can never be moral."
M.K. Gandhi

 

[Slowrider]

Thats great if it works for his style of building and gives him the sound he's after, he's wrong about the more contact thing but I suspect he knows that. There is a better contact with a glue joint period. They are a whole lot quicker and easier to do I'll agree and esier to setup Again there is nothing wrong with a bolt on they are just different thats all.

Hey Muttley, have to disagree with you on that glue joint. That would be like saying a metal bar welded in a lap joint on the outside is as strong and resonance worthy as a solid piece of steel. Never going to happen. If a guitar neck is screwed to the body with a Press Fit, it would only need 2 screws to hold the resonance charachteristics. Solidity is only available, through a solid mass, such as string from nut to bridge. You have to consider that any glue, "hide is best" or any gap...will induce loss of tone and sustain. That is why all guitar manufacturers claim to have more tonality and sustain.