1976 Yamaha FG-251 Repairs

The first step is to remove the neck.  I have to separate the fretboard from the top.  I use a 75W halogen bulb, a heat shield, and a couple of spatulas.  And tape around the fretboard and sound hole to keep from damaging the top.

Step 1.  Fail.  The fretboard is separated but the heel won't release.


I looked closely with a flashlight to find there's a heavy string of mahogany still connecting the heel to the neck.  And possible the truss rod head wasn't helping.  So I loosened the truss rod and muscled the neck off.  Not the best separation, but I'll remove all the loose "hairs" and it'll go back together fine.

Last night I cleaned up any loose wood particles and fit the heel back on the neck. Unfortunately the heel is very slightly larger on both sides. I assume it retained some moisture from the steaming and it'll have to sit for another day or 2.  

I can't do anything until the heel is attached and pinned!!

I also used ebony stain and filled the worn spots in the fretboard. As I figured, the spots are darker but still very visible due to the roughness of the worn spots.

Saturday I carefully drilled the holes in the corners of the heel to the truss rod hole. Started with 1/8" to get it up against the heel, and stepped it by 1/32" to keep it on center and not walk towards the finished edge, finishing at 13/64". They always seem to break into the truss rod hole. I guess that's a good thing, I can feel and see when it happens.





I coated the shank of a long .195 drill bit with a little oil and put it in the hole. Then put some epoxy in the holes, pushed the pieces of 3/16" dowel in, and added additional epoxy to attempt to fill the holes. After 10 minutes or so my mixed epoxy set up enough and I pulled out the drill bit. Cleaned off the drill bit with denatured alcohol, waited another 5 minutes, and put the drill bit in again to push into any possible epoxy shift. Did that 2 more times. I don't mind having to drill a little epoxy out of the hole, but I don't want it filled and running everywhere.






I let that setup for a couple of hours then fit the broken fretboard extension back to the guitar. It's a jagged complicated break with many little fingers. It went right back together. Got lucky again!! I had gotten out a 12" radius block to possibly clamp to the pieces to keep them inline (ALWAYS practice your clamping!!!), but I noticed when I did that the fretboard extension pushed up slightly at the 14th fret break. Of course! The fretboard extension had been bent slightly with the heel break. So I need to get the fretboard level at the 14th fret vs. the whole fretboard flat. I'm thinking of cutting a few grooves in the back side of the fretboard to allow it to flex slightly (but not break!!), so after the neck reset I won't rebreak this joint. After the neck reset the fretboard extension will need to be forced down slightly to reattach it to the top, or make a tapered shim.

I mixed up some more hot hide glue, heated the parts under my heat lamp, applied the glue liberally, fit the parts together, tapped them together with the plastic hammer, pressed the fretboard level at the 14th fret, dug the hide glue out of the 14th fret groove, cleaned up the gelled glue all around, and held it in place for a little while. It looks pretty good.  

AHHH!!!!! I LOVE THE SMELL OF HIDE GLUE IN THE AFTERNOON!!!!

After fix. The break on this side is at the 14th fret dot. You can see the bend of the fretboard starting at the full part of the heel.  


You can see a very slight crack in the binding above the end of the dovetail.

Started working on the neck reset yesterday.  Since there was such a large radius of lacquer in the corner between the heel and guitar body, the heel ended up with a .02"/.03" wide strip with no finish, and the face of the guitar has a radius of lacquer.  This area of the heel needs to be removed or it will be visible when the job is done, and the lacquer radius on the guitar needs to be scraped flush.  I can't pull sand the heel with the radius there.

After finishing that I have to undercut the heel so I'm only sanding a small area.  This makes the sanding go a bit faster.

Then, because there was almost no gap between the heel and the back of the neck pocket, I have to sand material off of the back of the heel, 1/8" at the bottom, and 1/16" at the top. This has to be done because once the heel hits the back of the pocket, you can't sand anything off of the face of the heel to change the neck angle.

Then I checked the neck centering and projection, and calculated how much needs to come off the heel.  The neck projected .04" below the bridge, I want it to project .07" above.  .04" + .07" = .11"/3 = approx. .04" off of the heel.  That dimension is marked with tape on the heel.

I sanded about .01" off the heel before stopping for the night, resulting in the neck projection of close to flush with the top of the bridge.

I haven’t done an update in a while. Didn’t touch the guitar for 8 days. Most of that was designing and building a new Neck Clamping Jig, used to partially string up the guitar when the neck is loose. It came out great.

2 days ago I tried the jig functionally for the first time. I installed the old low E & B strings, putting the B string in the high E position. The high E will break after 3 or 4 tightening/loosenings, the B should last longer. I found the neck was slightly off center, I had sanded too much off the treble side, and the action was still a little high (expected). I did some chiseling and sanding and mostly corrected it.

Yesterday I finished the corrections. And I started filling the small gaps in the finish in the heel area. As much as I’d like to shim the dovetail and get the neck back on, I should “pretty up” the external part of the joint. It’s going to take a few coats over a few days. Hopefully I’ll be able to glue the neck on next weekend.