Official Luthiers Forum!

I have a couple of big name bolt-on neck guitars, and in both cases the neck joint is not manufactured to be a tight fit. It is a good fit on the back surface of the neck to the inner surface of the neck cavity on the body, but at the sides of the joint there is a small gap on both sides. This is the case in both of the guitars I'm referring to, and in both cases the neck is secure and strong despite many years of use.

In the guitar I'm building I'm trying to figure out how important it is to have a tight fit at the sides of the neck joint. Is it enough to rely on the four screws that attach the neck? They will hold it tight, but they are woodscrews and so there is a limit to how tight they can be made, and if they start to get strained then the joint won't hold.

The joints on the manufactured guitars I have seem to be strong enough, so should I just be ok with having a good mating surface for the back face of the neck joint and not worry about the tightness of the sides of the joint?

Thanks in anticipation of your responses.
Ant

The tighter the better the sustain, also a loose joint can cause the neck to move around no matter how tight the screws. I had a guitar with a loose joint and when I would pull on the neck it would shift enough that the e string would slide off of the frets when freted. I ended up shimming the sides of the pocket and it helped, but I was never happy. I just wasnt stable enough and the sustain wasnt as good as it could be. This was on a jackson fat strat, fender era.
They say you should be able to pick up the the guitar with no bolts on the neck and the body should stay on. I always get great sustain with a guitar this way, I make mine tight enough that I have to scrape the pocket to bare wood for the neck to fit, you can always sand a little if needed. I would never buy one that a thin guage pick will fit between the neck and the pocket.
Hope this helps,
Terry...

Thanks Terry,
Yes, I see your point. It just seemed to me to be less structurally sound with a lose fit at the sides, and even though some big name manufacturers do it, that doesn't make it ok. It seems to me that there would be too much shear stress on the screws when the neck is pulled to the side for any reason, and I guess that would explain the movement problem you mentioned.
Cheers
Ant

A good joint in any application should have no gaps. As a woodwork teacher I always expected my best students, and encouraged the less confident, to produce joints that held themselves together without clamps but did not require excessive force to assemble. What I used to call "friction held".

Are you sure that the sides of the neck pockets on the "Brand" guitars aren't just arrised (rounded slightly) and are actually good tight joints further down? Can you slide a piece of paper right down into the gap or does it stop after only short distance.

The guitar I've just built could be picked up by the neck without mechanical fastening prior to finishing and after painting and clear finish was very tight to assemble. After removing the screws I really need to work the neck out of the pocket to remove it.

Actually, yes. Maybe Gibson don't do much with bolt-on necks, but I have a Gibson electric on which the neck pocket has a good 1mm gap each side! It was clearly built with the expectations that the screws, and the friction of the joint faces would be enough to stop the neck moving. To be fair, it's an old guitar and the neck's never had any movement, but I agree that it's an inherently weaker joint that way.

Cheers
Ant

Here's the problem with Bolt-on neck fit. If it's too tight a fit, during the dry months you risk getting little cracks at the corners of the pocket. You see these on a lot of old bolt-ons. If it's too loose, it looks sloppy. No matter what, even if it's tight today, during the summer you'll likely have a small gap. It's best to keep your bolts tight as even a tight pocket will allow the neck to move a little if the treble side of the pocket is short like most Fender style pockets.

Good point, Sheldon. So, I guess I'm wondering whether I can do better for hardware to make the joint more robust and durable. Currently I'm using the standard type of 'bolt-on neck' screw, which is really just a woodscrew with a deep thread and either a faceplate or ferrules to bed the head. What I'd like is a real nut and bolt alternative, but there are problems with selecting the right hardware. Firstly it has to be able to match the choice of finishes, so I need to be able to chose from chrome (or nickel), gold or black finishes. Secondly whatever 'nut' the bolt screws into has to be fitted to the neck before the fingerboard is attached, since it needs to clamp across the neck, but not the fingerboard. Does anyone have any suggestions?

Thanks
Ant

Lots of your favorite music was played on guitars with gappy bolt on necks...

_________________
Jordan Aceto
Ithaca, NY

Ant,
I assume your talking about performing this operaton on new necks and not the models you already have. I have 2 ideas for you to consider.

Idea #1 would require the routing of two short recesses parallel to the edges of the neck heel and truss rod on the fingerboard side. Into these you could glue (or just place) two metal plates that have each had two holes drill and thread tapped to line up with the bolt holes in the neck and body. Then glue your fingerboard over them. These would have to run along the length of the neck otherwise they would interfere with the truss rod.

An alternative is to design a complete unit incorporating the truss rod. Either a single drilled and tapped plate or 2 bars across the rod in a fabricated assembly. The truss rod adjustment may have to be at the headstock end but possibly not. The truss rod that is a simple steel C-channel with a round bar inside would be easy to weld to if you have a reasonable MIG. Even brazing (hard solder) with Oxy-Acetylene would be strong enough. This would not interefere with the operation of the truss rod and your bolts would not strip out of steel in a hurry. The whole assembly would be routed into the neck as part of the truss rod preparation.

The routing required would not be too tricky if you made templates up. Certainly no more difficult than any other routing skills required to complete a guitar. As its all hidden under the fingerboard tolerance is important but appearance not so much.

If your not clear from my description I could make a sketch for you.

Glivo - that's an interesting thought. I suppose the simple equivalent to that would be to set a nut and washer into the neck on the fingerboard side so that, similarly, the fingerboard would cover it. That way, the recesses could be drilled at the necessary angle for the neck set angle and any strain on the nuts would be avoided. The nut and washer could be potted in epoxy so they don't move around when the neck is unbolted.

I like the idea, but I'm still trying to see how I could match the 'gold' or ' black' finishes for the rest of the metalwork. The chrome may not be too easy either.

Doesn't someone sell bolt-on neck hardware that isn't a woodscrew? There must be a nut/bolt solution available somewhere, but I just can't find it!

Thanks for your thoughts
Cheers
Ant