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I just had an accident - I dropped a guitar neck I was finishing up and the heel broke in two when it hit the floor. I'd like to be able to salvage the neck by gluing it back together without the break line showing. What glues and techniques should I use to accomplish this?

Here's a picture:

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Max Bishop
Brighton, Michigan

Max
The key to this fix, as you probably know I'm sure, is not so much the glue as it is the fit.
If when dry fit the joint is invisible then most wood glues should work. titebond orig, elmers, etc.
if you can't make a good dry fit, it looks like you can though, I'd wait for further advice. There'll be lots I'm sure.
Ken

Ken is right, the glued joint will only be as invisible as the joint fit will allow. That said, I feel that hot hide glue leaves a less visible line than Titebond, especially in lighter wood. It also pulls the joint tighter as it dries.

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It will probably be alright.

Greg has said it all. HHG is the best way to go. Pull the threaded gizmo out before gluing. Probably was the root cause of the break, just needed a little force to knock the heel off. Why I like dovetails...

Excellent point. The insert was probably installed on the tight side and started a crack. Would probably make a good joint impossible if left in for the gluing.

I don't know the best glue for invisible lines, but my experience with fish glue is that it isn't that great for transparent glue lines. I love it for all the other properties it has, but since I started using it, I've had to accept a little more visibility in joints,
Mike

What the others said. However, if you happened to use an epoxy grain fill, gluing with a clear epoxy (e.g. WEST) will give a virtually invisible joint if the fit is good. And you get plenty of time to make get the fit right. Whichever way you go, make sure your clamping will be stable when the glue is on.

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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 would be tempted to plane it off parallel to the finger board, and build a stacked heel. A little more work, but it will look purposeful. Maybe try the repair first, and if the glue line is visible ( I think it will be), then fall back on the stacked heel.

As others have said, I would remove the insert and use hot hide glue. If I'm looking at this correctly, it appears that there is a slot next to the insert which doesn't help the joint. I would fill the slot. Then I would drill down through the heel and glue in a dowel. Then I would redrill for the insert. That way the threads hold better in the side grain of the dowel rather than the end grain of the heel and the heel is more stable.

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Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

Much like what Ken said. I use two 1/8" maple splines far enough apart so that the insert threads engage the maple but there is still enough spline material left to reinforce the heel. Easy if the fretboard is not on. In this case I would pull the insert and glue with HHG or epoxy (per Trevor) then put in two 1/4" dowels to provide support for the insert threads and heel reinforcement. If the slot in the heel is full height then I would fill that before installing the dowels. Just my $0.02

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Steve Smith
"Music is what feelings sound like"

I won't get into the "best" discussion that can be problematic depending on one's opinion. I have always used Titebond Original -- including soundboards, our "prep and clamp" routines are geared toward producing a perfect surface match, end result is a virtually invisible glue joint. I believe these two factors are key no matter what joint is being assembled or adhesive that is used.

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Ken Cierp

http://www.kennethmichaelguitars.com/

YES
Tom

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A person who has never made a mistake has never made anything!!!

Hi again Max
Lots of good advice but having a second look at the pics, I see the real fly in the ointment is not
just having to make a good wood to wood glue joint but one with finish on. The wood is broken cleanly along grain lines but the finish is probably cracked all over the place. (at least on a microscopic scale) That's hard to hide unless you're planning on refinishing the area. Others, more experienced, might disagree but I would refinish the heal area and be done with it. Type of finish you have there depending, of course.
Ken

Ken said what I was going to say. The only thing I would add is another reason I would choose HHG. If I didn't like the way I got it clamped the first time and the glue line showed too much I could take it apart and re-do it without having to remove glue (and wood) making the fit worse the second time.

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Bryan Bear PMoMC

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

Thanks to everyone for the advice. BTW, that is not finish on the neck, but epoxy pore-fill.

Thanks

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Max Bishop
Brighton, Michigan

You should be good to go then. Glue it up, some more pore fill and you'll know under a wet coat
of epoxy if it's acceptable to you or not. Just the visual aspect, I don't think strength will be a problem. Let us know how it goes.
Ken

Also, when driving the dowel rods down into the holes make sure you flute the rods to allow air to escape other wise you will be compressing the air inside the holes while hammering in the rods. Or like Steve Smith says, better with the fretboard off and you won't have this issue.


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"After forty-nine years of violin building, I have decided that the search for a varnish is similar to the fox hunt. The fun is in the hunt."
Jack Batts Maker and Repairer of Fine Violins

Thanks again to everyone. I followed Trevor's advice and used epoxy because of the epoxy pore-fill. It worked out great and another coat of epoxy pore-fill made the fracture invisible.

Max

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Max Bishop
Brighton, Michigan