Martin Neck Question

[Photojeep]

Hi,
I posted this same question on the General Information forum because I didn't realize we had a Build and Repair one... Sorry about that...

Anyway, I was recently told that my Martin DCPA4 Siris had a bolt on neck which could be reset rather quickly because of this.

What I've since learned is that it has a Mortis and Tenon neck that contains a bolt used primarily as a "clamp" to keep things together while the glue dries.

I've also read many believe this bolt is what provides the majority of the "holding together" force for this type of joint as the glue portion isn't actually strong enough to hold things together by itself.

My question is, Does this design make it easier/faster to do a neck reset? My guitar is not in danger of self destruction any time soon, but its saddle is about as low as it can go while keeping the playing action decent and the break angle of the saddle could certainly be greater.

I hope some luthiers or repair folks here can shed some light on such a situation.

Thank you and sorry again for the "double post",
PJ

[John Arnold]

At most, it is 20% faster than doing a dovetail reset.

[charles Tauber]

Originally Posted by Photojeep

Anyway, I was recently told that my Martin DCPA4 Siris had a bolt on neck which could be reset rather quickly because of this.

Not true. It's near the same level of effort as a "regular" dovetail.

What I've since learned is that it has a Mortis and Tenon neck that contains a bolt used primarily as a "clamp" to keep things together while the glue dries.

Also not true. Martin calls the joint a "simple dovetail". It is a dovetail joint but, unlike "regular" guitar dovetail joints, is one that is not tapered along its length. Furniture, particularly drawers, are put together with "simple dovetail" joints.

http://martinrep.com/joints.html

I've also read many believe this bolt is what provides the majority of the "holding together" force for this type of joint as the glue portion isn't actually strong enough to hold things together by itself.

If the joint is properly fitted, it has more than enough strength. It is a mechanical joint. if well fitted, the glue only prevents lateral movement of the joint that would allow the joint to separate.

My question is, Does this design make it easier/faster to do a neck reset?

Not very much. One still has to get the glue in the dovetail joint to release. One still has to detach the glued underside of the fingerboard from the top. One still has to refit the joint and heel to change the neck angle. One still has to reglue the neck and fingerboard. One still has to deal with the change in fingerboard plane over the top where the neck angle has changed. All of these are more or less the same whether on a "simple" or "traditional" dovetail joint.

Contrast that with a guitar that has a neck attachment that can be reset without any gluing/un-gluing, adjustment of heel/joint fit and fretboard extension that can be accomplished in 20 minutes or less. Then there are designs that allow the player to adjust his or her own neck angle simply by turning a screw or bolt.

[Photojeep]

Thank you very much! I suspected what I'd heard was a bit over simplified, not to mention the bit about glue not being the primary adhesion for the joint.

This may be an unfair question to follow up but does anyone know the range of prices a neck reset on such an MT joint might cost?

Mods: If this is an inappropriate question, please ignore and delete this post.

Thank you again,
PJ

[charles Tauber]

Originally Posted by Photojeep

This may be an unfair question to follow up but does anyone know the range of prices a neck reset on such an MT joint might cost?
PJ

It is a dovetail joint.

Typical costs for resetting a glued dovetail joint is about $500, depending on who is doing it and where he or she is located. Assuming John’s 20% less effort, take up to 20% off that.

[John Arnold]

Charles,
I think you are describing the current construction. For many years, Martin did have a straight mortise and tenon joint on their lower priced models.

https://umgf.com/mortise-tenon-vs-dovetail-t87387.html

It does need to be steamed out, like a dovetail. But there is no fitting of tapered shims to refit after the heel is trimmed, since the sides of the tenon are straight.

If the joint is properly fitted, it has more than enough strength.

I built several guitars with a straight tenon joint, using only glue. None have failed.

Unfortunately, on these Martins, 'properly fitted' is not a given. I have had to add thin shims to achieve a decent fit. Many of these have failed after the bolt works loose, and may be the reason Martin adopted the simple dovetail.

[charles Tauber]

Originally Posted by John Arnold

For many years, Martin did have a straight mortise and tenon joint on their lower priced models....

Many of these have failed after the bolt works loose, and may be the reason Martin adopted the simple dovetail.

Thanks for the correction and further info.