question about archtop neck construction

[JazzNote]

On my Gibson archtops the necks include the extension in the same piece of wood, while Benedettos are constructed with a separate piece of wood for the extension. What are the advantantages or disadvantages of either?
TIA

[Skip Ellis]

I seem to recall the original JS neck, as he designed it, did not have the fingerboard extension - the fingerboard was down on the top; something to do with more connection of the neck to the body. Seems like I saw an article years ago where he describes it. Does the Heritage JS have the extension? I had a 70s JS for awhile and it had the extension and was still a nice guitar. As to why Benedetto does it, I don't know; I've only built one full blown archtop and it was before Bob's book - I had to call him a couple times in PA, to straighten some things out during the build. If I had to guess, I'd say it has to do with making it easier to cut the dovetail on the neck as it would be very difficult to do it with the extension being a part of the blank and also making final neck angle adjustment easier as well as getting the extension fitted properly to the top. Somebody correct me if I'm wrong about the original extension.

[JazzNote]

I seem to recall the original JS neck, as he designed it, did not have the fingerboard extension - the fingerboard was down on the top; something to do with more connection of the neck to the body. Seems like I saw an article years ago where he describes it. Does the Heritage JS have the extension? I had a 70s JS for awhile and it had the extension and was still a nice guitar. As to why Benedetto does it, I don't know; I've only built one full blown archtop and it was before Bob's book - I had to call him a couple times in PA, to straighten some things out during the build. If I had to guess, I'd say it has to do with making it easier to cut the dovetail on the neck as it would be very difficult to do it with the extension being a part of the blank and also making final neck angle adjustment easier as well as getting the extension fitted properly to the top. Somebody correct me if I'm wrong about the original extension.

Skip, it's not only the Johnny Smith, also the L5 and LeGrand has the fingerboard extension in the same piece as the neck. The difference is, that the L5 and LeGrand have it partially floating over the top, the JS not at all floating. My 1953 L7 however was built with the same method Bob uses, but the separation is exactly positioned where the body is attached to the heel.

[Skip Ellis]

Skip, it's not only the Johnny Smith, also the L5 and LeGrand has the fingerboard extension in the same piece as the neck. The difference is, that the L5 and LeGrand have it partially floating over the top, the JS not at all floating. My 1953 L7 however was built with the same method Bob uses, but the separation is exactly positioned where the body is attached to the heel.

What I meant was, the earlier ones did not have an extension at all - the fingerboard sat right on the body. I found a good photo of a '69 online that shows this but couldn't get a link to it. I believe he got upset with Gibson when they started using the extension and told them to take his name off - maybe why he went to Heritage?

[Jimmy blue note]

Guitar necks are one of the places where choice wood, especially in regards to grain orientation and straightness are concerned is crucial. Quartered is most desirable and has the smallest yield in a cut log, and flat sawn is the next desirable (stable). Because this is mostly for the extension from the heel (neck join) on up, the part that overhangs the neck above the body is not as important.
The heel is sometimes built up in separate blocks (in classical construction, this goes clear into the neck 'foot' that glues to the top and back) and that saves on the sheer wood use while offering grain variation to minimize any long grain twisting or splitting tendencies.

This "prime wood" requirement means that if you can use straight quartered wood on the neck itself, and use a more generic wood in the block and body segment, you can save wood, a lot if you're on a large production.

Full length one piece construction will obviously give the greatest consistency but whether the part blocked under the fingerboard and comprising the 'chin' acually adds to any practical advantage...I'd say it's academic. It's not as pretty but not crucial for strength in my book.

It's more an executive decision for aesthetics and prestige, I think good wood on the neck, the heel, chin and dovetail/tongue in groove, that's not such an issue for neck straightness.
By the way, I happen to like the stability added in a three or 5 piece neck. That's more than a pretty stripe, it adds good torsional stability from counteracting pieces.

Hope this helps. One person's opinion anyway.

[Jimmy blue note]

By the way, I know back in the day John D'Angelico, being basically an artisian builder, could choose any wood he wanted, it was probably easy(ier) to use one piece necks. Why not? So he made them that way and it worked out really well for strength and ease of work for him.
Johnny passed his D'Angelico built design to Gibson and was known to want it as true a piece for piece replication of his D'Angelico, even it went against Gibson's own construction practices. So for Gibson Johnny Smiths and their direct offshoots, they were as close to John D'A's guitar as you could get outside the Kenmare shop.
This changed during the Norlin era when Gibson made changes to the design which Johnny Smith was not happy with. I believe it was at this time that Johnny Smith guitar stopped being made with that name but I'm not sure. Inception of the LeGrand?

[deacon Mark]

My 37 New Yorker has a 2 piece neck and the extension is all part of the 2 pieces. The 49 New Yorker has a one piece neck and the extension is all part of the neck. They vary and don't ask me why except it depends on the piece of maple used. The action of these guitars is quite stable and does not change from season to season and I live in the midwest.

Necks and attaching them are quire individual to the maker. Basically, they find the way this is the most efficient and will allow the neck set to go fast and smooth. Setting a neck on a guitar is one of the most trying things because you have to get it right the first time. If you prepare well it goes smoothly usually. That said, neck can be made with one piece, two, three, and five depending on how you count. How the neck is glued in the dovetail is something different in that some want the extension glue to the top. This would be Johnny Smith because he wanted the highs to be transmitted to the top and felt this accomplished it the best.

Bill Hollenbeck did not do this and neither did Bill Barker they simply had the extension running just slightly above the top. My Heritage Johnny Smith also has the extension running into the top. I might note my Heritage Johnny Smith is a killer acoustic guitar with plenty of volume and has not trouble standing up to guitars made without extension glued. The small piece of extension you have is normal and not wrong. In fact there really is not many absolute rights and wrongs it just depends. Having seem how Mark Campellone attaches his dovetails I would say he is the Master and has mastered the process.

[Freeman Keller]

In my humble opinion having a separate piece for the extension makes carving the dovetail infinitely easier. I use a simple little home made router jig and if I had the extension in the way it would be impossible to route. Following Bob's advice I used carbon fiber to strengthen the joint, if anything it makes the neck almost too stiff







I did make one guitar where the extension is not floating, it is still a separate piece but is glued to the top and is simply a continuation of the neck stick.