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I am curious about different approaches to attaching a neck to a thin line hollow or semi-hollow guitar. I have seen the Gibson approach of a thick tenon that extends two or three inches into the body, but it begs the question of why so different from the dovetail they use on a ES175, for example.

I understand that the thin line semi's all have a center block that can be routed to accept the long tenon, but did Gibson do it other ways as well? Almost everything they do they have done differently before. Also, how about a full hollow thin line like the Epi Casino or ES-350? How is the neck attached in them? Do other makers like Gretch or Hoffner make full hollow thin lines? How about Sadowsky or other "modern" makers?
Anyone know how they handled their neck attachment?

I am planning a thinline, and I would love to see what has been done before.

Believe it or not - bolt on necks will work provided the block is secure to the top, bottom, and sides.

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I've built a couple of thin line semi hollows as well as a couple of LP style guitars using the long tenon - works fine. Gibson did make some short tenon 335 style guitars - from what I read those have a lot of problems.



Guitars like ES175 and L5's don't have the big center block so they use a dovetail. I don't believe that you have enough body depth on a thin line.



Both tenon and dovetails do require that you get the geometry perfect while building. Here is the worst of all worlds - its a short tenon that was poorly fitted and glued. The body joins the neck at some really high fret and to make matters works, its a 12 string neck on a double neck, It was just asking to fail, I told the owner to expect it to fail again



There is no reason not to use a Fender style screw on neck (I hesitate to call them "bolt on" unless you put inserts in the neck and actually use bolts). Screw on necks have lots of advantages - you can be sloppy with the geometry and shim them to work perfectly. Its also a little bit harder to make a screw on neck that blends into the rest of the guitar - they always look, well, screwed on.

So, I guess I'm a snob. If I'm going to go thru all the trouble of making an elegantly carved or shaped top (and back) I'm going to take the time and effort to make a neck that flows into the body. I'm going to take the effort to make a elegant joint. If I'm going to make a slab guitar I'll screw the neck on like Leo did.

Thanks @Chris Pile. I took you to mean “bolt on” in the sense of a lag screw or insert in the heel and a bolt through the head block like a typical flat top acoustic. Is that what you mean?

@Freeman, is it your understanding that a dovetail would be too short to hold a 1.75” heel as opposed to a 3” heel? Makes sense, but I’m just wanting to make sure I understand. Have you ever seen or heard of a “bolt on” neck as I’m describing to Chris (not a Fender style “screw in pocket” neck)?

Also, do you know how the neck is attached in a Casino or ES350? I asume they have traditional neck blocks that you couldn’t do a long tenon as in your first picture. But I can’t find pictures of their interior. Do the have a “head block” that extends to under a neck pickup allowing the long tenon?


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BTW @Freeman, I don’t think I’ve ever seen a fingerboard extension that is glued on to the body as an apliqué separate from the actual neck. Is that common or something you came up with?


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I mean like Leo Fender did it.... with 4 screws and a plate.

_________________
"Act your age, not your shoe size" - Prince

When talking about electric guitars, most people use the term "bolt on" to refer to the Fender style four screws with a plate like Chris says. A few people actually install threaded inserts and use bolts - probably a good idea if you plan to take the neck off very often. That is a perfectly acceptable way to build any electric guitar, has some real advantages. Just make sure your geometry is right.

The other use of the term "bolt on" is as Taylor and others (including Freeman) do it on acoustic guitars. Two threaded inserts in the neck heel of (usually) an M&T joint





Not practical for a thin line for a lot of reasons, not very practical for archtops because its hard to get to the bolts without a nice sound hole.

Dovetail of course is the multi angled joint that pulls the neck heel against the body as the tenon is set into the pocket. Elegant wood working joint but I don't think there is enough surface area on a shallow guitar to make it work very well. I use them on archtops and traditional flat tops but frankly prefer bolts.

The Gibson style mortise and tenon relies on the glue joint to hold the neck to the body. Gibson has used it on lots of guitars so I think it has a proven track record. I like it on guitars where I want the neck to blend into the body.



The bid disadvantage that I see is that you have to get the geometry right when you set it - there is some adjustment in most modern bridges but I try very hard to be comfortably within the range.

I included the picture of the archtop to show the dovetail joint and the fact that the neck heel flows into the body. Most archtops have some sort of overstand built into the geometry, some more than others (I've worked on some Gretsch semi hollows that seemed to have a lot). This gets complicated by the shape of the top in that area - because of the single cut on the treble side the top drops off more than the bass. I just added the little platform for the neck extension on top of the body and leveled it to the fretboard plane. It was kind of a challenging thing to fit

Thank you @Freeman. I personally use "bolt on" (in the sense we both were using it) for my archtops. I access the bolts with a long tool I made to reach through the end pin hole. Not my own invention, I copied it from a builder 10 or so years ago on MIMF.

I have never loved the Gibson "long tenon" neck. Basically the neck extends all the way to the theoretical 24th fret, but is carved back creating a shoulder at the body join. The tip is then further routed down to make room for the pickup. As you say, the geometry has to be right and it cannot be adjusted once glued in. Mostly, however, since I don't intend to have a full center block I couldn't see how you would do that on a full hollow. A 2"x3" "tenon" would leave a tiny donut of a neck block. So how is it done on a Gibson 330/Epiphone Casino? Weirdly, I can't seem to find an image or description by searching on Google.

Does the neck block extend into the body half way? Did they use a dovetail and neck block configuration similar to the L/ES full hollowbodied guitars? I know a Casino isn't very popular except with Beatles fans, but thousands were built. Whatever they did must have been stable enough. Any ideas?

I do not know how the Casino is build. Wiki says its is a "true hollow body guitar" However this pictures



shows me two things (at least). First, that is a stud mounted ToM which implies that it must be mounted to a block of wood inside. As you know, archtops with ToM use the floating version that just sits on the top. Second is that is a B70 style Bigsby that has the two mounting screws down into the top (located right at the hold down bar). Again, that requires a hunk of wood inside. There are other Bigsbys that are designed to mount on the thin top of a hollow body.

It is possible that instead of a big center block there is some sort of framework of bracing that supports the pickups AND the bridge/tail piece. My L5 clone was made that way - I did use a floating bridge and a trapeze tailpiece but it would be very easy to put a couple of cross braces in there for the studs and Bigsby. BTW that is same guitar as my second picture - it does have a dovetail joint



So, short answer, I don't know...