Thread: Bolt on Dovetail

My research indicates two schools of thought, neatly divided into about a squillion sub-schools. Some schools seem to think that glueing the neck onto the body can retard the tonal qualities of the instrument, like sandwiching a bit of rubber between two sheets of timber, and therefore is undesireable. they prefer the tonal qualities of bare (and bare is VERY important) joints pressurised together by bolts or wooden spline pegs. Taylor guiars went one further with three bolts, one going into the fretboard from underneath, completely removing glue fom the neck/body join.
See here:

http://www.frets.com/FRETSPages/Luth...t/99joint.html

I'm not suggesting that we all go out and try and whip up something similar (but wouldn't it be nice) but Taylor seem to have an excellent reputation and sound and there is NO GLUE in this joint.

There is definite reason for bolt on from the perspective of future neck resetting, where you only have to remove the fretboard from the top, not unglue a dovetail as well.

I guess it comes down to what method of machining your willing to go to. The bolt on mortice and tennon style is pretty simple and straight forward, everything is right angles and square to the centre line of the guitar, the dovetail is anything but.

Don't go looking for a "this is better, or worse" thing, cause there is no such thing.

Go to the local music shop and from my experience the cheapo guitars seem to have some sort of dovetail/glued in neck and the expensive ones are mostly bolt on.

I hope I have muddied the waters for you even more

Yeh Mongrel your a
Mongrel that help a lot
Clear as Mud !

I thought it might be one of those questions. I am fairly confident at cutting the giant blind dovetail but if you cut a good joint and fit and glue well it would be near impossible to ever get apart again without risking damage to some other part of the instrument trying to get it apart. I can also see that modern glues which are stronger and more flexible may not be as helpful to the acoustics as a more brittle traditional glue used in this joint.

The more I think about the bolt on idea the more I like the idea. Only thing that worries me is the threaded insert. I dont think I have ever seen one of these things go in straight and its not like you get more than i chance with this joint. Although I can think of a couple of ways of using bolts without threaded inserts at all.



Ross

my experience has been in fitting dovetail necks in the past..
For my own personal build I decided to go the bolt-on method for my current one.....I am using knockdown bolts with barrel nuts instead of the threaded method..same as this
http://www.cumpiano.com/Home/Article...headblock.html


whether you decide to go the bolt-on or dovetail way, its all similar when it comes to actually fitting the neck for neck angle, neck twist, and getting it aligned with the centre line..there's usually still a bit of fiddling around to get it just right.

which sounds better? who knows ....there's a lot of factors to consider which contribute to the end result..I'd place more emphasis on the bracing than any other factor.

Couple of other good links:

http://www.stewmac.com/freeinfo/Rout...ts/i-4783.html

http://www.frets.com/FRETSPages/Luth...rianreset.html

I like the pinned idea thou, no bolts, everything snug and easy...ish

Thought you guys might like this quote from Will Cumpiano authour of "Guitarmaking Tradition and Technology"

"So what are the alternatives? The tapered dovetail joint? Heavens, no! If there was ever a joint designed in hell, that one is it! There is little to be said for the joint to recommend it to hand builders. For us, the tapered dovetail is unnecessarily complex, requires endless fussing to get it to fit properly and as well, to disassemble it for resetting."


Ross

The pinned M&T is the joint i use exclusively because even a dolt like me can get it to fit square and straight. That said there are a lot of builders who use dovetails with terrific results. Its about being accurate. As for the sound... shape, volume, bracing, bridge placement, timber used will all be much more important than the joint used.

Also a word about the glues used. Hot hide glue has to be the glue here as the joint can easily be separated if it needs to be with the application of heat. Epoxy, PVA etc are a major PITA. The bolt is even easier if you leave enough room in the soundhole for a hand.

Personally, I've never used a dovetail join on a guitar. The only reason they were used in the first place, is that the glues of the day, couldn't handle the stresses without some additional, structural joint assistance.
While I can see the sense of a removalble mortice and tenon joint (and I may try that, one day), I've actually never used that either.
Bolts also sound like a good idea, I never got around to trying them.
I've done the traditional classical guitar neck/body join, where the sides are let into the neck block, but only when I've had no choice.

I use the join that no one else dares mention....
The BUTT JOIN!
...with epoxy.

Most modern adhesives are literally stronger than wood. With a butt join, you can postion the neck accurately without all that endless fiddling about with jigs, fitting tenon shoulders etc.
And before you ask, I've made 13 or so guitars and never had one fail.
Boy that's going to set the ravenous cat among the pigeons.

Originally Posted by paulplaysguitar

Personally, I've never used a dovetail join on a guitar. The only reason they were used in the first place, is that the glues of the day, couldn't handle the stresses without some additional, structural joint assistance.
While I can see the sense of a removalble mortice and tenon joint (and I may try that, one day), I've actually never used that either.
Bolts also sound like a good idea, I never got around to trying them.
I've done the traditional classical guitar neck/body join, where the sides are let into the neck block, but only when I've had no choice.

I use the join that no one else dares mention....
The BUTT JOIN!
...with epoxy.

Most modern adhesives are literally stronger than wood. With a butt join, you can postion the neck accurately without all that endless fiddling about with jigs, fitting tenon shoulders etc.
And before you ask, I've made 13 or so guitars and never had one fail.
Boy that's going to set the ravenous cat among the pigeons.

No cats or pigeons from me I am sold on the bolt on for now but would love to hear or better yet see more of how you do your butt joint.

Ross

I would also love to see your butt.... joint.

OK, here's one to throw into the mix, the bolted butt joint. This has been in the back of my mind for a LONG time. I just wonder whether I can machine it accuratly enough

Never forget the VERY original spanish heel, thou its not vey good at all for a neck reset Originally designed with gut strings in mind.

Or then there is this beastie, which, as far as I can tell has the 5 bolt neck like its electric cousins
http://www.seanet.com/~jsd/ssid30.html

This is the "stephens extended cutaway" made famous (for me at any rate) by the Nuno Bettencourt N4 series guitars by washburn

I too, would see your butt, if it pleases you

Originally Posted by paulplaysguitar

I use the join that no one else dares mention....
The BUTT JOIN!
...with epoxy.

An expoxied butt joint on an acoustic is fine but lets just hope you don't have to do a neck re-set sometime in the future. If you're selling your guitars commercially then IMO you're setting up a time bomb for yourself.

A dovetail M and T joint is one of the strongest joints in cabinet making and contrary to what alot of people think the strength of this joint has nothing to do with the glue you use. If the joint is well done you can string up and play your guitar with the neck dry fitted (ie no glue on the joint).

I use dovetail joints mainly because I love a challenge. If I was producing guitars commercially Id definitely consider bolt on necks.

Cheers Martin

Originally Posted by Sebastiaan56

Also a word about the glues used. Hot hide glue has to be the glue here as the joint can easily be separated if it needs to be with the application of heat. Epoxy, PVA etc are a major PITA. The bolt is even easier if you leave enough room in the soundhole for a hand.

Hide glue joints are easy to undo but PVA and AR joints arent that hard to get undone either. Ive had the back off my latest classical three times now and it was just a matter of judicious use of a heated pallette knife. The bridge on my last steel string had to come off and it only took about 30 minutes to gently prise it off.


Cheers Martin