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-   -   Jumbo 12-string Neck removal despite epoxy. (https://www.acousticguitarforum.com/forums/showthread.php?t=467555)

Darryl Hattenha 04-22-2017 12:02 PM

Jumbo 12-string Neck removal despite epoxy.
 
If a neck is glued in with epoxy, can you remove it it? Would you have to take off the back and gouge out the neck block etc?

thomasfelty 04-22-2017 02:58 PM

The first guitar I built was from a David Russel Young book. The neck didn't have a tenon or dovetail but was a butt joint that you used epoxy to affix to the body. To remove the next he said to hit the neck hard near the joint and that would break the glue joint. It worked. I did have to re glue a small peace of the side back in place. I did remake the neck with a tenon and used hanger bolts to tighten it to the head block. If you have a tenon that is been glued in place I think you'll have to use heat to loosen the joint. I don't know of any solvent that will soften the epoxy. Good luck.

Darryl Hattenha 04-22-2017 03:57 PM

Thanks, Thomas. There's hope.

Howard Klepper 04-22-2017 04:23 PM

Is this the neck that is to be replaced because it's broken in three places?

Saw it off, then rout a new dovetail mortise.

Many epoxies can be softened with heat, but the problem is getting enough heat into neck joint without also disassembling the block from the top and sides and back.

Why do you think it was epoxied? Guild didn't do that.

Darryl Hattenha 04-22-2017 04:59 PM

Thanks, Howard.

I don't know if it's epoxy or not, but somebody did a bad neck reset, and I suspect it's epoxy.

If the neck gets put in with routing and a new mortise, would it show? (Sorry if that's a dumb question.)

John Arnold 04-22-2017 10:27 PM

There are methods to do this. I prefer removing the fingerboard and drilling into the joint with a long, thin drill bit (~ 1/16" diameter). You can remove the whole fingerboard, or cut it and just remove the section over the joint. Instead of cutting the fingerboard at the body junction, I prefer to cut it 2 frets up the neck. With a 14-fret neck, that means cutting at the 12th. This allows the fingerboard to overlap the joint when it is reassembled, which will be stronger.
I drill 4 or 5 times on each flank of the dovetail, then apply heat. If the end of the dovetail is glued, I drill there, too. If it is epoxy and not some other glue, I don't use water.
When the neck is reglued, the drilled surfaces are leveled, and thick shims are installed to compensate for the material removed by drilling. Most every dovetail reset involves installing shims, or replacing thin shims previously installed with thicker ones. At this point, the only difference from a conventional reset is the thickness of the shims.
This method has been successful on older Yamaha's, which are notoriously difficult to remove by steam injection.
Quote:

If the neck gets put in with routing and a new mortise, would it show?
No. The dovetail is smaller than the neck heel....usually at least 1/8" on each side. Guilds have wide heels like Gibsons.....much wider than the dovetail at the bottom. So even if the newly cut mortise in the neck block is slightly larger, it still will be covered by the neck heel.

Darryl Hattenha 04-23-2017 10:21 AM

Many thanks, John. Now all I have to do is rob a bank to pay for this.

Mr Fingers 04-24-2017 08:33 PM

Howard Klepper is correct about epoxy yielding to heat. It softens somewhat and then breaks down (with an obnoxious smell) into a white powder. I removed a heavily epoxied saddle (!!) from a slotted bridge by using a soldering iron. Took 2 hours. If you cannot get a controllable heat source right onto the epoxy, this will not work. I would be tempted to do as some suggest -- cut the neck off, repair/redo the joint -- a dovetail or mortise if you want, but even a bolt system is possible -- and reattach. Good luck. I, too, built my first good guitar from the David Russell Young book, and it has a butted, epoxied neck joint. I took the time to fit it properly, and it hasn't budged in... 42 years!

Darryl Hattenha 04-24-2017 08:37 PM

Thanks, Mr Fingers. I had heard that epoxy made things impossible, but now I'm feeling like this job is going to happen


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