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I cut on the wrong line.. and as a result my tenon is only 1/2” . Is this too shallow?
I generally use 10mm barrel bolts to do my bolt on. It would still fit but ho early won’t leave a lot to grip

Should I try to extend the tenon w a glue on?

Or should i scrap it?

Hanging my head after making a dumb mistake


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Include a couple pictures please.

Easier to give advice if we can see what you got yourself into

You could do a loose tenon, and maybe even improve the grain orientation of the tenon by turning the grain 90 degrees to the grain of the neck:
https://www.woodcraft.com/blog_entries/ ... on-joinery

One difference from what is shown is that you would only glue the tenon into the neck and bolt it to the body.

Option 1: Hack that tenon off and convert to butt joint.
Option 2: Use Gore style square bar instead of barrel bolts http://www.luthiersforum.com/forum/viewtopic.php?p=715113#p715113

Yup, Gore style if you have access to a 10mm or maybe 3/8" mortice drill.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Trevor does post here on occasion so he may correct me on this but I believe the bolt bar may have originated with his co-author Gerard Gilet, or at least have been a collaborative effort between them both.

(Also once you try bolt-bar, you won’t go back )

It sounds like your using the "Cumpiano " style bolt on mortise and tenon. Just make 2 thin plates the correct size of the side of the tenon that you originally wanted, cut down the tenon thickness to accommodate them and add a block on the end to fill up what was accidentally cut off and glue it all up. Also you can improve it by turning the grain of the "plates" 90deg. to the end grain of the neck for added strength. I make mine like that all the time, except I try not to have the little block on the end.

I reinforce my tenons by gluing on a strip of thin aero modellers ply on each side of the tenon. I use 1.5mm thick which may help with Mike Spectors suggestion.

Hey guys sorry I haven’t responded yet.
I’m at work so I can’t snap a pic, but the issue is the tenon is too short. I like a 7/8” tenon vertically.
To use the 10mm barrel nut will leave too little wood on the bottom (under the nut) and I fear it would pull out eventually, although probably not.

As the suggestions above … I could reinforce the sides of the tenon so that the dyes of the barrel nut are grabbing onto that, or possibly glue an extension onto the end of the tenon so that it sits perfectly in the mortis and has no where to go. For that matter I could just cut a shallower mortis and achieve the same thing . The mortis hasn’t been cut


This, as with most things I mess up can be rectified ha.
See the high tech illustration below



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TBH, I think your neck is lost unless you find some radical save. FWIW, when I still did a tenon, I would glue on a cap of rosewood or maple to the face of the blank before I routed the tenon. I know it's not proper joinery to glue to end grain, but, it seemed effective to prevent the barrel nuts from splitting the tenon. While most folk seem to reinforce that area by adding shims to the sides or the tenon, adding meat to the end did seem to work. YMMV.

Also, if you haven't shaped the heel, you could perhaps try a butt joint with threaded inserts...

Sure, you'd have bolts going through a lot of empty air but so what.

Actually you could drill a round hole down the heel and install the barrel nuts vertically like the square bolt bar. Drill a couple of small holes through the tenon from the side and glue dowels to eliminate any possibility of splitting.

You also could lay on some carbon fiber or glass on the end of the tenon to strengthen it.
All of the above suggestions seem practical to me.

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Jim Watts
http://jameswattsguitars.com

Switch to hanger bolts for this one and be done.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Yes, the square section bolt bar originated with Gerard with the bolt-on, glued down fret board neck joint, sometime in the 1970s, I believe. I developed the concept into the bolt-on, bolt-off neck joint (double tenon with bolt down fret board extension) some 35 years later.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I had a "student" builder who would bring his guitar parts to my shop for tips on his next steps. He built three necks before he got it right.
Even though I hate it, I toss a part from time to time.

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I tend to keep the mistakes hanging on the wall as a reminder. I finally tossed a half dozen necks this summer because I realized I don’t need THAT many reminders. :-0


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If there weren't so many good options for rectifying the relatively minor mistake, then I might agree that tossing or repurposing the neck might be the best option. Since the mortise has not been cut, removing the tenon and making a simple butt joint with inserts or hanger bolts would work fine. If keeping the tenon and barrel nut is wanted then making a loose tenon and turning the grain90 degrees to the wood in the heel would actually make a stronger fastening than the usual one piece construction.
To learn from your mistakes you sometimes need to overcome them.

I don't disagree with you Clay, especially if the OP is a learner. Just the idea of wanting to use the mortice and tenon joint, and switching over to a bolted butt, being a "bridge too far". There is something liberating about starting over. In my early days, starting over was how I proved to myself that I could build the guitar I wanted to build.

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True David. The other side of that coin is that sometimes recovering from mistakes opens up your repertoire.


This could be an opportunity to try a butt joint and decide he likes it. Not much to lose but time if starting over is the alternative. Arguments on both sides have merit; it is up to each of us to weigh these types of things out for ourselves. That is one of the things I love about this forum. If you post a problem, you get lots of different approaches from lots of people. Some may work better for your personality and situation than others but considering all of them really can open up your eyes to techniques you hadn't considered.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

One of the drawbacks of the barrel nut/ bolted tenon as I see it is that the grain of the tenon is going in the "wrong" direction. By cutting a mortise in both the neck and the body the "loose tenon" can have the grain oriented in a better position and a stronger construction made. If I were to do bolt-ons with tenons that is how I would do them.
But I am the lazy sort and I don't feel barrel nuts installed in tenons as they are conventionally made are any stronger, I generally do butt joints with inserts.

Thanks for suggestions guys. I think I can keep the neck. Ill experiment and see what I can come up with.
Still can’t believe I made that mistake
That said I don’t look to make it again.
1 out of 25 isn’t bad I guess


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Googling loose tenon


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I'm thinking that a loose tenon is the same thing as a floating tenon? Neither of which is loose or floating.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Yea I’m finding that out:) a floating tenon should be floating:) I mean….


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