1972 Yamaha FG-500 - Neck Reset+

DAY 2 (7/25/24) – Put Gluboost Master Shield heavy plastic tape on both sides of the heel corners (to guard against a possible slip) and cut thru the lacquer radius with a new scalpel blade. Used the .010” thick saw to cut thru the heel cap. Used the scalpel to cut the lacquer radius around the fretboard extension.

Put the heat shield on the top and heated the fretboard extension with the halogen light, moving the guitar every 5 minutes, trying to get under it with the spatula’s after 20 minutes with some progress, getting under about 1”. Put a towel inside the guitar. Injected some hot water into the space and pushed the spatula in further. Put the spatula back in, put the heat shield back on, and heated for another 10 minutes, and pushing the spatula under some more. Pulling the spatula out finds GLUE on both sides of it!! And repeated once more, before finally getting to just short of the 15th fret. About 45 minutes total. The fretboard is loose!

The Gluboost tape, which is meant for sanding, but I've also used it while cutting.


The tape in place.


After cutting into the heel corner.


The other corner.


Cutting the heel cap.




Scoring around the fretboard extension.






The tools.


Heating the fretboard extension.


Found glue!!  That is a very good sign.  It means I'm between the pieces of wood. Most of the time the spatula digs into the top after it gets past the rosette.  It could still have dug in farther in.


Almost there.


At full depth.




Done!

DAY 4 (7/29/24) – I put the tape on the heel corners and pushed the scalpel in the whole length of both sides to be sure that isn’t the problem. Then put guitar back in the neck jig, turned the steam on, alternating holes, end pressure and wiggling after 4 minutes, no difference. Turned the steam off at 7 minutes, the joint is tighter, the left side of the heel lamination is loose, the bass side is getting there. I’m loosing faith that neck will be coming out in 1 piece.

I let it sit in the jig for 18 minutes to cool and turned the steam back on. I let the steam go until it ran out at 10.5 minutes. No change!! It is very loose at the top, but the bottom has the tiniest of movement on the bass side and none on the treble side! I removed the end pressure and let it sit for 20 minutes. I put a screw type clamp between the heel and fretboard for no particular reason, The gap under the fretboard is up to .07” with zero movement at the end of the heel.

I turned the steam back on, doing wiggling with no end pressure, hoping to get steam into wherever it needs to be and loosen the joint. 4 minutes of wiggling with no end pressure, then increasing the pressure, and finally feeling some progress. More pressure, more wiggling. It finally popped at 8.5 minutes!!! WOW!! With all that wiggling I’m amazed the heel lamination didn’t separate!! The extreme wiggling was the only way I was ever getting the neck off, but I was sure it would have caused the heel lamination to fail.

I’m not sure where it was stuck!! There was a large wad of hide glue at the bottom of the dovetail that was flexible but not wet. With all the water that was pumped into the joint, some of that leaking out of the bottom, I’m amazed that a wad of glue at the bottom could have been what kept the neck from coming off. There was also a small piece of the side stuck to the bottom of the heel in the same area.

I scraped some of the glue off of the surfaces. I turned the steam back on the heat the pickguard tail so I could clamp it flat. And also heated the treble side top binding that seemed to be bulged up slight, and clamped it down flush. There is some separation of the top from the neck block, and some of the top was dug into during loosening the fretboard. While it was still wet, I scraped off a small piece of the top that was stuck to the bottom of the fretboard. I’ll look at all of that tomorrow after it has had a chance to dry out some.

And I clamped the neck heel in the stew mac guitar vise to hold the heel lamination closed, although it didn’t seem to be swelling open as it sometimes does. The heel will be pinned on both sides. The biggest problem is going to be the growth in the length of the heel due to all the moisture that was absorbed during the excessive steaming. That will not return to where it was, even with clamping pressure. The body is 3.75” thick and the neck, the heel measures about 3.85”, .10” longer. By far the worst I’ve ever seen. Maybe it will shrink a little. Maybe I’ll have to cut the heel and reglue it to shorten it.

Looking at the previously hardest successful neck removal, this 63 total minutes of steam beat the previous 61 minutes. And the NINE steam sessions (over 2 days) beats the previous record of EIGHT!! That is NOT a record I ever wanted to beat!!

While editing the pictures I noticed the upper treble side binding was loose, so I reconfigured my clamps, adding a 24” clamp to hold the binding flat. I will glue it tomorrow, I just want to be sure it stays the right shape.


You can see the treble side binding and top slightly separated.


A very thick shim on the treble side of the neck pocket.


Nothing on the bass side.


A small piece of the top stuck to the bottom of the fretboard.  You can see the small piece of the side stuck to the heel below the dovetail.


There was a small shim on the bass side.




Dug into the top when separating the fretboard.  I will glue that tomorrow.


Closeup of the loose top parts.


And the curled pickguard.


Clamped the heel.


Supported the headstock.


Clamped the top binding and pickguard.


Changed the clamps to add a 24" clamp to hole the side binding in place.


The top protected in case to clamp get dislodged.

DAY 6 (8/2/24) – Put tape around the heel area, and sanded this and the fretboard extension area smooth.

I used the chisel, file & sanding block to get the neck joint back together. It’s just short of going fully in, which will be fixed as the sanding is done to fix the neck angle. I’ll leave the heel mismatch for now.

Then I pinned the cracks in both sides of the heel, using a 3D printed compound angle drill jig that slips over the dovetail, and clamped it against the bottom of the fretboard. I drilled 13/64” diameter x 4-1/4” deep holes, and epoxied 3/16” diameter hardwood dowels in. First, I put tape around the holes to protect the guitar finish, dropped the epoxy in the holes, rolled the dowels in the epoxy, pushed the dowels in and held them for a few seconds (to push out all the air in the hole), scraped up the excess epoxy, waited about 10 minutes for the epoxy to set, and removed the tape.

Sanded the heel area smooth.


Sanded the fretboard extension area smooth.


Clamped the heel drill jig.






Drilled the holes.  I used to do this by eye, and in diameter 3 steps, which was risky.






With the drill jig, I get the holes in the perfect location every time.






Ready to epoxy the dowels in.

DAY 8 (8/4/24) – After I went to bed I realized I was excited that the fretboard was very close to level, but I never checked the actual frets! Checking the frets with the straight edge pretty much parallels the findings with the notched straight edge, about .005” max, having to take the material off a few of the upper frets. There's a chance there could be a few high/low spots that can't be seen with a straight edge.

As I mentioned in the initial assessment "The first 12 frets are .029” to .033” high, which leaves next to nothing for leveling, I like to see .025” min after leveling. The upper frets are .033” to .036”. This is good because the area that needs the leveling is the upper frets, which are the highest. But there will be nothing left for another leveling. 

The only advantage of refretting is the new frets start as .043" high, and level a few thousandths lower, leaving more than enough for fret leveling in the future.

There is one disadvantage of a refret. There will be gaps at the ends of the fret slots, and probably nicks in the finish from filing the fret ends. Yamaha sprayed the finish on the guitars after they were built, filling the fret end gaps. In that case, I'd go with just the fret level to keep it minty looking.

He agreed to just level the frets to keep the minty look.

Checking the fretboard and fret level.

DAY 10 (8/8/24) – Made the new bone saddle. It sticks out of the bridge .22”/.19” (B/T), a good place to start.





Examined the steam holes at the 15th fret to find they will be covered by the fret. Put a clamp on the width of the fretboard to protect from blowing out the lacquer in the ends of the fret slot, and used the 0.4mm (.016”) & 0.5mm (.020”) saws to clean out the 15th fret slot. Sanded the 15th fret area, with the grain. Used the 3 corner file to break the corners on the slot (to make getting it back in easier), and banged the 15th fret back in.

After cleaning out the slot and breaking the edges.


After banging it in.






Removed the nut, first putting a piece of masking tape on the headstock behind the nut, using the scalpel to score the glue line on the sides of the nut, and pushing the scalpel in from the back until the nut pops off.

Ready to cut under the nut.


Almost there!


It's out!



Taped the fretboard. Used the scalpel to cut the ends over the fretboard extension so they don’t hang below the bottom edge.

DAY 12 (8/13/24) – I had thought about sanding the bass side heel lamination area, but it’s a very slightly swollen mismatch. I think if I try to sand it flush I’ll sand thru the finish and make a much bigger mess. I colored the treble side heel lamination crack with the mahogany marker. Then polished both sides with the Dremel and small polishing wheel.

Made center marks on the neck at the 1st & 12th frets, and on the bridge. Inserted the neck into the neck pocket and verified the neck projection at about .06” ABOVE the top of the top of the bridge, although the neck isn’t perfectly seated yet. Checking the neck alignment with the straight edge, it looks to be centered.

The end of heel isn’t perfectly flat, and there’s a very slight gap along most of the heel corners, so I set the tape on the heel end at .02” and filed to the tape. This was rather difficult due to the 3/16” thick maple heel cap.

Then I pull sanded the heel 3 strokes on both sides. I noticed the neck isn’t sitting flush on the body all the way around. I check the depth of the neck pocket and find .53”. And the length of the neck dovetail is .56”. The neck dovetail is hitting the back of the neck pocket!! I made a mark near the end of the neck dovetail 7/16” from the face of the heel, drew an angled line to the top corner of the neck dovetail, and sanded a wedge off of the dovetail.

The neck is sitting a bit better against the body. Did some more pull sanding on both sides to get the neck and heel very close to flush all around. The neck is still centered and projects about .08” above the top of the bridge. Time to put the guitar in the neck jig and see where the action is with string tension.

Put the guitar in the neck jig, installed the old strings, and tuned to “D”. The strings are centered. The neck relief is good. The nut action is a little high, as expected. Capoed a .013” feeler at the 1st fret to simulate approximate proper nut action. The action is a little over 1/8” low D, and 1/8” high D.

About to file the end of the heel cap.  This reduces the chance of it popping off while pull sanding.


Made the angled line on the dovetail.


Sanded to the line.  This is to relieve the back of the dovetail so I can continue sanding the heel without it hitting the back of the neck pocket.


Pull sanding the heel.



First stringing!!  The action is still a little high.