Neck joints - Separating the myths from the facts

[tippie53]

The point is any joint that is well secured and good fitting will be adequate. I think there is the notion that a bolt on neck is a lot easier than a dovetail. I can say and I am sure Sylvan and Rick will agree that any good neck joint takes skill. There are no shortcuts. The heel of the neck must fit the body so that the neck angle matches the bridge and saddle height, action line, fret plane and relief all match. Center line of the neck matches the body and that the joint integrity is clean and tight.
How the bolts are attaches and the method used won't matter as long as they can withstand the stress applied, after that it is a visual thing.
Neck resets are inevitable and how the neck is attached may facilitate this more than a dovetail, however a standard reset is about 15 to 20yrs down the road in most cases.

[Darryl Young]

It is mentioned a couple of times that neck resets my be 10+ years out. My experience is that while many may wait 10 years before getting a neck reset, the guitar may have had a bit too action where it's more difficult to play for 5 years or so before the owner gave in and had the neck reset. Most folks won't spend the money for a neck reset till the guitar gets in pretty bad shape.

I think this is is a "pro" for a bolt-on neck and maybe a "con" for dovetail necks. You can often reset a bolt-on neck in 10-15 min so it's much less expensive so can be done more often. So it seems it's more likely that a bolt-on will be kept in pristine playing condition all the time vs a dovetail neck. At least it would be much, much cheaper to keep a bolt-on neck in ideal playing condition vs a dovetail neck. That's the main point that appeals to me. I can't tell you how many Martins I've played that had very high action and needed a neck reset but the owner lived with it as they didn't wan't the guitar gone for 3 or 4 months and/or they didn't want to spend $400 on their old guitar. I don't recall playing a Taylor with very high action.......but if I found one, it could quickly and cheaply be cured.

[sylvan]

I have refrained from stating my preference in neck joints precisely so I could get some input from everyone first. As a point of fact all of my instruments are "double mortise and tenon" NO GLUE. I arrived at this position by first trying the epoxy butt joint, dovetail, pinned mortise and tenon, mortise and tenon with fretboard glued down and, now to a completely mechanical joint. I do for two reasons: 1) it allows almost immediate neck resets without damaging the instrument and 2) there are times when I estimate the saddle height I need and I am just flat wrong; in the old days that meant at least breaking the fretboard loose to readjust the neck angle, sometimes causing other damage (usually finish) which had to be repaired. With the mechanical joint, I can reset a neck quickly and accurately, so much so that when an owner needs a saddle adjustment many times I just reset the neck. I have about 150 guitars out "in the wild" that I need to worry about. Neck resets are no longer a worry for me.
But, as I said earlier, if you are happy with your neck joining operation, stick with it! If the guitar holds together and sound great that is all that matters!

[tippie53]

While I may be a traditionalist I can say I agree that the adjustment factor on a well designed bolt on is not a bad thing

[sylvan]

John asked me if I would be willing to post photographs of my neck joint system. So many have helped me in the past it is a pleasure to pay it forward. I hope this helps everyone in their maturation as an expert builder. So, here you go!
One caveat: these are photos of a guitar in paint and not buffed out yet. The neck has been fitted and will bolt right up once the paint is sanded and buffed.
One photo is of the top of the guitar. Notice that the hole for the tenon is quite small. It is just behind the transverse brace and just large enough to fit the tenon which is glued to the underside of the fretboard. I used to rout all that away but I found that it is quite important to the integrity of the guitar that as much of the top remains glued to the block as possible. Also the transverse brace is scalloped at the ends only about 1/2" from the linings. It is left as beefy as possible.
The other photo is the tenon which is glued to the fretboard. There a two 8-32 inserts. The bolts that hold them in place are invisible since they are located behind the transverse brace. It is a bolt, lock washer and washer. They are only tightened until you feel the lock washer engage. No need to crank them down! Also note the two inserts on the end of the tenon. Their location is not critical as long as the lower one is at least below the middle of the tenon. I fit these after the guitar and neck are made. It is different for each model I make. They are not standard distances. I try to position the lower insert as far down the tenon as I can get.
I hope this helps.

[tippie53]

Thanks again Sylvan
In the movie El Dorado James Cann's character said something that I find pertinent and I quote
" I have a host of friends "

[sylvan]

I forgot in the last posting two things. Firstly, the neck joint I am now using was jointly developed over a couple of years of e-mails and photographs with a very good builder in Minnesota, Terence Kennedy and one of my former students in Frankfurt, KY, Will Renshaw. I also spoke with Dana Bourgeois who uses a similar but different setup. Hat's off to all of them!
Secondly, after looking at the last post I thought I would be remiss if I did not post a photo of the underside of the top so everyone can see the rigid transverse brace and the piece of spruce that ultimately spans the top from the headblock to the transverse brace. That piece is what is routed out to allow the tenon to fit. It also is slightly larger than the largest fretboard I use so that there will be no fingerboard cracks in the future in the top. Grain direction is the same as the top so there will be no expansion/contraction issues.

[B. Howard]

Slvan, Very nice system. One question that I have is do you do anything to address the fact that the FB extension may not sit tight on the top in all situations? Appears that it would not really be a true floating extension like an archtop and also may not appear to be tight as those that have the extension glued to the top.

[sylvan]

Brian -
Obviously the bottom of the fretboard must be flat for it to fit properly. If it isn't perfectly flat for some reason, I chisel up to the last 1/8" edge of the fretboard (much like undercutting the edges of the neck tenon) so that it will lay flat. Most of the time if you are careful in the construction of the fretboard, it will be flat and fit nicely.