Martin Dovetail Neck Joint

[Oldsoldier]

I've started a build of a Martin 000 kit, my first guitar build after successfully doing several ukulele's. As I completed constructing the rim, I thought I should test the neck to neck-block joint before I went further. After inserting the neck firmly into the dovetail I noted a space of 1/8th inch, perhaps a little more than 1/8th, between the back wall of the dovetail and the neck tenon. Otherwise, there is a firm connection of the neck to the rim. Is this amount of space in the dovetail acceptable/normal?

[Danl8]

Yup, that's normal. I asked the same question and posted pictures, too, in 2014 when I did my first.

[Oldsoldier]

Thanks for your reply. That's encouraging.

[Bob Gleason]

That space is there for a couple of reasons. First, it would be difficult to get the neck down tight after you put the glue on if the excess glue did not have a space to run to. 2nd, that space is what allows you to get steam into the joint to remove the neck if necessary, and it will always become necessary at some point in that guitar's life.

[Oldsoldier]

Makes sense! Thanks.

[Oldsoldier]

Another question on the Dovetail neck joint. On the tenon near the bottom, there is an inset threaded brass nut that points to the neck block when the neck is installed, and there is a partially drilled hole toward the bottom of the Dovetail opening; but there is no hole through-and-through the neck block nor a corresponding bolt in the provided parts to connect to the brass nut. Is this an optional connection of the neck to body or am I supposed to drill all the way through the partially drilled hole and put a bolt through it and into that inset brass nut? I have not seen this addressed in any of the literature I've read.

[tippie53]

that has nothing to do with the actual guitar. That is used in the finish production . It is screwed to a line that goes through the finish area. DO NOT USE A BOLT .

[Oldsoldier]

Thanks, John.

[Oldsoldier]

I have my neck joint set to my liking, my fingerboard fretted, neck and body finished, truss rod installed and about ready to install the neck. I have not glued my fingerboard to the neck yet. Would it be unorthodox to glue the neck on and then glue on the finger board after the neck glue has cured? The reason I ask is that my neck without the fingerboard locks right into the dovetail when I tap or clamp it in with the neck angle right on, centerline right on and neck flush with the top (with very thin shims). When I try to tap it into the dovetail with the fingerboard attached to the neck (with rubber bands, not glued) the fingerboard extension is in contact with the guitar top and doesn't allow me to tap it into locking like I see the woman do on the Martin factory tour video. Doing this in dry fitting, it appears to me that I could glue on the neck, then after it sets up, glue the fingerboard to the neck and body simultaneously, but I didn't know if there would be unforeseen problems by doing it in that manner. Any thoughts?

[Bob Gleason]

The fact that your fretboard extension touches the top and won't let your dovetail seat tells me your neck set is off. Sounds like a little too much forward tilt to the neck. It will be pretty difficult to get the neck angle set exactly right without having the fretboard on first. Not impossible, because we do that on classical guitars, but it is a completely different style of building, without a removable neck joint. If anything, there should be a little space at the sound hole end, not much, under the fretboard extension when the neck joint is seated properly. To get the neck angle tilted back, you will probably have to remove wood from the male part of the dovetail., and then most likely you will end up with a wood shim in there. Don't be afraid of doing that. 99.9999% of dovetails end up with a shim of some size. Just use the same wood as the neck is made of and make it tight. Don't be tempted to mess with the female part of the dovetail joint, only work on the male end.--Bob