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I recently strung up a new guitar. The neck joint was nice and tight. After I got tension on it for the first time, the neck pulled away by about 1/64th or so. The bolt doesn't seem to want to suck it up anymore. Any easy suggestions?

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Any way of checking to make sure the bolt isn't maxed out thread wise? I use barrel nuts and always make sure the bolt has enough room to go all the way through.

I use threaded inserts. I checked to make sure it wasn't maxed out before I glued on the neck. It does seem to be a little loose as if the insert is now twisting though.

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My guess is that the insert is loose in the heal. It might be pulling loose. I would check it before doing anything by taking the tension off and removing the bolt and seeing if you can close the gap with some pressure applied to the heal. That's not a good thing if the fretboard is glued down. I use barrel nuts, so i haven't really had that problem and can't help much on a fix. I would think you'll have to remove the neck to fix it though.

Can you post a pic of the type of insert you used?
Pat

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I get these from home depot. Can't find a picture of the bolt online, but it is pretty typical.

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I've also have used those inserts. It's possible your insert has popped out of its hole. Bummer...if that's the case here. I found that this insert tears the wood up a lot when tapping in. That makes for a dangerously weak and gripless insert. I had to drill the pilot holes slightly larger than the suggested hole dia. to keep from tearing the wood badly while tapping them in. After setting the insert all the way in, I removed and reset with thick CA. I now also use 2 inserts instead of one for bolt ons.
KB

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that insert is not a good thread design . I use the Brass inserts , the same ones that Martin uses . Never had on fail . The threads on this really tear up the wood grain . I will try and post a pic of the brass ones asap

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John Hall
blues creek guitars
Authorized CF Martin Repair
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For all the bolt on builders? I just curious why folks dont use the barrel nut method anyway?

Jeff

The bolt might be going through the thread and hitting the bottom of the hole. Then if you wind it in more it will start stripping your insert out of the neck.

Is this a mortice and tenon neck joint? If so the tenon might be reaching the bottom of the mortice, before the heel touches the guitar sides. This is likely if you have removed some of the heel to alter the neck angle. In this situation you need to deepen the mortice in the heel block.

There was a good discussion of neck bolt systems recently on the Australia & New Zealand Luthiers Forum. Here is a link - some good thoughts on inserts versus barrel bolts.
http://www.anzlf.com/viewtopic.php?f=1&t=2604
cheers
Mark

Jeff - I use the barrel nut with allen-head furniture connecting bolt method all the time. It's a winner IMO. FYI, I CA-glue the barrels into the cross-drilled holes in the tenon once they are positioned correctly (being careful not to get glue in the threads though!).

Cheers,
Dave F.

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Cambrian Guitars

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I use a dovetale joint on the neck. I know that the bolt is not bottoming out. Would it be possible to add a screw of some sort to suck in the gap?

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A properly fit dovetail shouldn't need a bolt to pull it tight. I've done bolt on dovetails, but no longer do. Gluing one in is much simpler. Either way a dovetail need to fit tight without any thing extra pulling it together.

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I use the threaded hex drive inserts pictured above. They're designed for end grain with the large barbs and require a 3/8" hole. I bevel the hole, clamp around the tenon and slowly drive the insert with a hand drill. The key is to run thin CA around the insert (hence the bevel) to lock it in place and solidify the end grain. I never had a failure, and got this method from working at Pantheon where 1000's of guitars are built with that method.
I do not use barrel nuts because I feel it is too much work for little to no gain IMHO, but principally because the large holes for the barrels make the tenon much more fragile.

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Laurent Brondel
West Paris, Maine - USA
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Dave thats the method I use also.....I really like it too

I'm not a fan of inserts. I've never used barrell bolts, but don't see the need. To me it seems like a complex solution to a simple problem..........but again, I've never used them. I use hanger bolts. I counter sink the holes and cover the nuts with a label. I prefer dovetails but for some clients neck joint type can be a dealbreaker.
Collings uses hanger bolts, Martin uses inserts, but also glues the neck. Taylor uses a piece of aluminum that's got a couple threaded holes planted into the neck. I've never wanted to make a guitar like a big company, but with things like attaching the neck sometimes they have the best ideas. Do any big companies use barrell bolts?

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http://www.brackettinstruments.com/

I like hanger bolts for a bolt on, with a dowell rod glued in to aid in crossgrain hold. Although it does require more accurate alignment of the bolts, the pull out resistance is incredible.

Chuck

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I've used both inserts and barrel nuts. I've settled on inserts because I think the shear
forces on the end grain when using barrel nuts could get too high very easily. And if
you CA glue the barrel nut in place, you've lost any advantage they have over the inserts.
I've tried both the coarse thread version shown and the finer thread brass. I like the brass.
I drill slightly larger than the root diameter of the insert, drive very carefully, then glue it in
place with CA glue. I haven't had a problem with this method. I wasn't using CA when I
gave up on the coarse thread insert- I may give them another shot using Laurent's
technique.

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Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

I do the same thing as learned from Mario. I drill the neck block holes a 1/16" or so larger. Never had any alignment problems yet. Very strong as Chuck says.

More allowance than hanger bolts going through oversized holes?

Granted I've only built one guitar but, it was a stew mac kit with the hangar bolts. I wanted to make a real domed top with profiled sides as practice for my next bandura build so I built a sanding dish and profiled away. Needless to say, the neck joint geometry was not totally different and the holes in the heel block didn't line up anymore. I just filed away with a round rasp until they did and it worked out just fine. Very sloppy when the nuts weren't tight but I can tell you - LOTS of room for alignment error. Who knows though, maybe it will explode in 15 years.

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Hi woodyb,
As far as I know no big companies use the barrel bolts.....might be a good reason for that...I'm not sure! I think William Cumpiano uses this method? I trust his judgement and technics. And for added security I always do this on the tenons...three splines...two on the outside and one thru the center. Who knows if it will hold up? I'll probably be dead by the time it fails! If it does.

I have two questions, what are the hanger bolts? The second one is when using the inserts what size bolts does everyone use?
Mike

A hanger bolt is a stud, half of which is threaded for a nut ( like a machine bolt) and the other half threaded like a lag bolt (wood screw). Most bolt on builders are using 1/4" diameter.

Chuck

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Thanks Chuck, I've used hanger bolts before for other things. I would imagine that they are easier to install, but are there any downsides to them?
Mike

Could the trussrod be interfering just a bit? I use the bolt, but not with a dovetail, it's hard visualizing both together.