Gibson neck join - how on earth do you get the thing off?

[Tavy]

This rather nice A4 has come to me for repair (believed to be 1930's, but lost it's label so no serial No. to be sure), fingerboard came off nice and clean:



From the side you can see the issue - it had a bridge cut to the absolute minimum (below it actually) and the action was still truly terrible:



So... how the blazes do you get the neck off? I'm using a steam cleaner with a needle attached to blast steam into the pocket behind the dovetail (and this thing really does blast out steam), but about an hour on and the thing is still rock solid

The glue line round the dovetail was rather thick (probably why it pulled), and I can push a knife blade almost all the way round the dovetail to a reasonable depth, so I assume it's hanging on by the heal? I could use a razor saw to separate the heal from the body if it's a butt joint, but I don't want to start that in case it's inset in a mortise. It's hard to see what's what and where the seams are under previous signs of repair and touch-up. Anyone have any photo's of these taken apart so I can see what's in there? How did you separate the heal? For a neck that's pulled so much this thing sure is solid!

A related question - how much of a structural element is the fretboard? The board on this one was nicely done at some point, but is now just 3mm thick at the nut end, and the fret slots are less than 1mm from going all the way through. I'd hate to put it back on and then find that the truss rod won't hold it straight...



Many thanks in advance!

[David Houchens]

The heel button and back can hold tight to the bottom of the heel even after the dovetail is loose. Insert a narrow spatula between the heel and the back. I wouldn't saw it as this would remove wood that would have to be put back. A warm spatula and gentle pressure should work. As it starts in you could work some warm water into the joint to help as well

[David Houchens]

Gibson oval hole mandolins usually have pretty stiff necks. The fingerboard shouldn't be a problem as long as its sound where it laps over the dovetail to the body. I feel it does add strength there, but a good fitting dovetail will carry quite a load.
Someone may have sanded out divots in the board which are usually in the first position. Can save replacing the board itself or not always so pretty fill options.
All this being said, a new board wouldn't hurt anything either. I don't know if it would have helped the bulge at the hole or not. Possible neck block loose at the top? Extra support there can't hurt.

[Bernie Daniel]

This rather nice A4 has come to me for repair (believed to be 1930's, but lost it's label so no serial No. to be sure), fingerboard came off nice and clean....A related question - how much of a structural element is the fretboard? The board on this one was nicely done at some point, but is now just 3mm thick at the nut end, and the fret slots are less than 1mm from going all the way through. I'd hate to put it back on and then find that the truss rod won't hold it straight...

I suppose if you wanted to save the original fret board and still beef it up up could glue a thin layer of ebony on the back side?

[MikeEdgerton]

At one time they wrote the serial number under the label in pencil. Is there a Factory Order Number stamped on the neck block?

[Tavy]

Thanks for the thoughts, it sure is stuck fast. There are a couple of (old repaired) cracks in the heal and one in the neck itself starting from the corner of the dovetail which I assume were all put in by the last guy to muscle this off, so I don't want to use too much force. Fretboard is possibly non-original anyway... it's just a little more work to replace. I'm aware of the FON, but haven't looked hard for it yet.

Thanks, John.

[Bernie Daniel]

Thanks for the thoughts, it sure is stuck fast. There are a couple of (old repaired) cracks in the heal and one in the neck itself starting from the corner of the dovetail which I assume were all put in by the last guy to muscle this off, so I don't want to use too much force. Fretboard is possibly non-original anyway... it's just a little more work to replace. I'm aware of the FON, but haven't looked hard for it yet. Thanks, John.

Hopefully, that "last guy" did not use some kind of glue down in there that does not melt?

[Tavy]

Hopefully, that "last guy" did not use some kind of glue down in there that does not melt?

Oh boy lets not go there! At least the glue in the dovetail is HHG, it's always possible someone tried to glue down a separating heal later I suppose, but I sure hope not.

Here's the problem heal, as you can see it's so well glued down I can't even see where the join is supposed to be - that's the problem really I can't get it clear in my head where it's supposed to separate. Looking at those old cracks too, I suspect this may have separated into several sections at some point?



FON is 712 BTW, can anyone date it from that?

[Vernon Hughes]

I've got a butt ugly 1905 A here that had a 50's style neck stuck on it-it needed to come off to have a proper neck built for it..I steamed it to death only to find it had a nicely embedded and well hidden honking 2" wood screw through the neck heel into the headblock..At this point i'd do some scraping around to see if that might be the case..Usually steaming a neck of an old A takes me 15-20 minutes. I'd put a new board on it at this point..my 2 cents worth.

[belbein]

so well glued down I can't even see where the join is supposed to be - that's the problem really I can't get it clear in my head where it's supposed to separate.

Boy, my first thought when I looked at that heel joint was: epoxy. Which does melt, at thermonuclear temperatures.

[mirwa]

Its evident its had repairs before, so make sure there are no hidden screws or pins inserted, apart from that steam the joint and apply constant even pressure at the heel and it will pop

[Paul Hostetter]

This rather nice A4 has come to me for repair (believed to be 1930's, but lost it is label so no serial No. to be sure)...

It's best to date it by the FON, not the serial number. That number should be inside somewhere.

The glue line round the dovetail was rather thick (probably why it pulled), and I can push a knife blade almost all the way round the dovetail to a reasonable depth, so I assume it's hanging on by the heal?

The heel? It may be hanging on because you've pumped so much steam in there that it has swelled up. Perseverance furthers, it'll come off. There are no secrets. I have photos of an A neck from that era—off—on my home computer, but I'm not at home. It's not important anyway. It's just being difficult.

A related question - how much of a structural element is the fretboard?

It cannot be underestimated. If the old board was planed in a failed attempt to make the action better, you'd be best to start over with a new board anyway. That said, those necks are pretty stout (and usually so stiff that the adjustable rod is completely ineffectual). But a wedge shaped board promises trouble if the neck is reset to a better angle.

[Tavy]

It's best to date it by the FON, not the serial number. That number should be inside somewhere.

As noted above it's 712, but I can't seem to match that up with a date from online sources.

I have photos of an A neck from that era—off—on my home computer, but I'm not at home. It's not important anyway. It's just being difficult.

Paul, if you can locate that photo I'd really appreciate it.

I decided to perform some "test excavations" around the heal, and I believe Belbein has it right - the heal pulled away from the body and somebody just shoved some epoxy in there - I wondered how the neck had pulled so far forward without the heal separating - and now I know

There's a resinous layer that's a good 1mm thick, about 5mm deep in from the side of the heal, and then a small void in the middle. I can keep picking away with the knife, but it's hard to do that without risking pulling out chunks of wood as well, so I'd prefer to just cut right down through the lot with the razor saw if I can figure out where it's safe to do so.

Here's where the excavations have reached - as you can see I had to remove way more finish than I would have liked to try and follow the resin line:

[MikeEdgerton]

That FON is associated with a 1933 A50. The specs are as follows:

Oval sound hole, bound top and back, single-bound fingerboard, fingerboard raised off the top, dot inlay, silkscreen Gibson logo,dark red mahogany sunburst finish. It was introduced in 1933. The model changed to F holes in 1934.

[Tavy]

That FON is associated with a 1933 A50. The specs are as follows:

Oval sound hole, bound top and back, single-bound fingerboard, fingerboard raised off the top, dot inlay, silkscreen Gibson logo,dark red mahogany sunburst finish. It was introduced in 1933. The model changed to F holes in 1934.

Thanks Mike! That pretty much confirms that the fingerboard is non-original given that it had no binding.

[mandomedic]

I've had to "Re-Repair" several old Gibsons like yours that had been epoxy'd..Never an easy process. I have some dental picks that I acquired years ago from my dentist (when I had teeth) that are sharp and angled. I picked away at the epoxy untill I could get no more, then reintroduced the steam to the necks and with perserverence and pressure they came loose. Only one in 45 years would not let loose, so I used a thin Japanese saw and cut it off flush with the body, dug out the tenon and made a new one, glued it to the neck and reset it.. Good luck.. You'll need it.

[Tavy]

Update: definitely not an easy process! Dental picks helped a lot, and pretty much convinced me that the epoxy went way down inside the dovetail, so I ended up using the old razor saw to take off the heel, and then the neck did come out - though only 'cos the top section was so badly fitted!

Lower down in the heel, even with unrestricted access I couldn't get it free - in the end I had to use a dremel to route out the remains of the heel - here's the socket in the body - lot's of archaeology here - the black stuff is all epoxy and as hard as anything (still needs scraping out), the white layers are shims (epoxied on obviously) from previous repairs:



Epoxy went all the way up the dovetail with the just the extension-block on top fixed in place with HHG to fool unsuspecting folks like me!

[mandomedic]

Congratulations on getting that neck loose. I know exactly what you have been through with epoxy. Been there and done that and should have the Tee shirt. Keep us posted on your rebuild and setup.

[Tavy]

I really hate angles... even more to cut off a perfectly good heel...



But it feels much better when you stop doing damage and start reassembling...



Still lots of reconstruction and fitting to be done on the dovetail, but mostly just waiting for the new mahogany to darken up to match the old...

[Pete Jenner]

Nice work Tavy. Looking forward to seeing the final result.

[Andy Miller]

Tavy, it really makes you appreciate those odd incidents where a neck joint simply softens up, wiggles, and slides apart just-like-that, doesn't it?

[fishtownmike]

I think epoxy should be illegal to buy for the average person. It's one of the most abused glues around. Makers advertise it as the cure all for every repair project. The average person doesn't really understand that what he's using it for most of the time is a no no. I can't count the number of musical instruments and antiques I have come across where epoxy has either ruined them or almost has.

[Bernie Daniel]

I think epoxy should be illegal to buy for the average person. It's one of the most abused glues around. Makers advertise it as the cure all for every repair project. The average person doesn't really understand that what he's using it for most of the time is a no no. I can't count the number of musical instruments and antiques I have come across where epoxy has either ruined them or almost has.

However, approximately 99.99% of the epoxy glue purchased is not for building/repairing musical instruments...

[Tavy]

However, approximately 99.99% of the epoxy glue purchased is not for building/repairing musical instruments...

Indeed, and the stuff does have it's uses, I'd just rather it wasn't on something that came to me!

[Paul Hostetter]

I think the alleged dangers of epoxy are incredibly overrated. Over the years I have learned to reverse simple aliphatics like normal Titebond, as well as epoxy and cyanoacrylates. The adhesives I detest are Titebond 2 and 3, Gorilla glue, and contact cement. Those may as well be irreversible. Epoxy is not so suchamuch.