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You won't be able to do a dovetail, Aaron. You need to form the tail part of the dovetail ( the male part ) and there isn't any wood on the heel to do that. You could do a bolt-on butt joint, though.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Really? With all the various choices of glues that are "stronger than the wood itself", I couldn't build a dovetail or some kind of tenon onto that neck? What about a pair of brass inserts and some bolts along with the glue to attach a block of mahogany to the heel for shaping once everything dries? Sounds like it would be pretty strong to me. I feel like there's a way. I know it sounds a bit kamikaze, but I've done crazier things that worked.

The thing I'm still unclear on is how to get the UTB off of the soundboard so I can fix the top. Any suggestions on that? I'm very limited in my knowledge of acoustic guitar build and repair. I'm an electric guy. However, I'm starting to delve into the acoustic side of things. What does everyone tell you? "Practice on scrap", right? Well... this guitar is scrap right now. Nothing ventured, nothing gained.

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

I can't tell squat from your pic... it's too fuzzy. Try to get some light in there.

Chances are the guitar was overheated, the glue under the UTB softened causing the crack, and then resolidified. You might start with an iron on the soundboard right under the fingerboard, and try to work the UTB loose.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Or maybe I can just pull it off with my hand like I did with the neck.

Sorry about the lack of light. Taking a picture of the inside of an acoustic is not easy. You're right though. My parents live in PA and it gets really cold in the winter. To make matters worse, they keep their house at nursing home temperature. To further exacerbate things, when they remodeled a few years back, they installed a furnace downstairs and I think it was dangerously close to where he used to prop his guitar against the wall. He doesn't play much these days so that guitar would sit there for weeks without being played. All that heat from the send of the furnace must have screwed up the bracing.

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Place a flashlight inside the box pointing at whatever you're photographing, or turn flash on...

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Above the "neck block" there is another block running perpendicular to it directly beneath the fretboard extension. The crack in the top seems to follow this block, whatever it's called. What should my point of reference be in this? Is the top supposed to be (theoretically) flat? I noticed the back has an arch to it. It's obviously a D-28 knockoff. Just thinking that when I get things loosened up, I'll need some way of knowing when things are back in their home, so to speak. Thinking one of my leveling beams with clamps to keep it flat while the glue dries. Yes?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Yes you can add a tenon or dovetail to the heel, but you already have dowel pins to position the neck to the body to help in the placement of a bolt and threaded insert and an alignment pin. There are many builders who do butt joint bolt-ons. I think Todd Stock uses that joint on some of his guitars, so maybe he can step in and better describe the process than I can.
Another consideration is whether the heel block inside the guitar can accomodate a dovetail or tenon.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Yeah... I started thinking about the fact that the alighnment holes are already there. I just like to make everything more complicated. Bolt on is a better play here.

The sides don't flex. The top will flex a little with clamp pressure but not much. Overall it's solid, just displaced. The finish is poly. I can smell it on the areas I've cleaned up with sandpaper. I also smell that wonderful Brazilian rosewood smell. My dad said this was made right before export was made illegal.

Thanks to everyone for helping out with your advice. I know I seem like a special ed case. I'm just trying to minimize my mistakes. I'm learning a lot.

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Oh yeah...

Filippo, I couldn't even get a .002 feeler gauge under the UTB so the downforce of the neck obviously reclaimed it nice and tight. The block under the FB extension is slightly wider. Maybe 1/4"? Not sure what it's called or what the purpose of it is.

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Just because the UTB is firmly glued doesn't mean it didn't move. The glue probably softened due to heat and solidified when the top displaced. In any case the UTB needs to come off in order to correct the displacement.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Ok. The UTB is removed and the underside of the soundboard is cleaned up. It appears as though it bowes up on the far edges. It's hard to tell because it didn't exactly come out all in one piece. The one side did but they must've used more glue on the other side.

Regardless, now that it is no longer dragging the top down, the top all but reset itself. With a pair of clamps on the block thingy below the FB extension, I'm able to bring the top to an acceptable level. Now, the question is - Do I need to "reset" the block under the extension or will the new & improved UTB serve to keep everything in place?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

If the top lays the way you want it, I see no reason to unglue the block under the fretboard extension.

I'm also in the camp that says convert to a bolt-on neck. I see no advantage to converting to a dovetail and you could introduce new durability issues easily.

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Formerly known as Adaboy.......

Yeah... It took a second but I'm totally on the bolt on bandwagon now.

The top doesn't naturally sit flat without some coaxing. It's close but I'm thinking the shift that happened wasn't isolated to just the UTB. When I clamp the block under the neck to the top, it seems to lay more like it should. I can see evidence in the rosette that the area below the FB extension has shifted slightly toward the bridge though. Kinda like a glacier. It's subtle but still visible. What I'm thinking is I may have to coerce the top into place little by little while applying heat until that block goes back to it's home. When I run a straight edge across the top from lower to upper bout, I can see the top is sunk down around the sound hole. Now, of course, in the absence of the UTB this makes sense but there is also no string tension on it at the moment. Should I work to get the top flatter before installing the new UTB?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Make a new, beefy UTB with a flat gluing surface and glue it up. The brace will flatten the top very easily. Just make sure you clamp it well (critical).

I'd say the fretboard side. It's more of a long bow between the two and not very deep. Not like a bridge bubble. I've seen that before.

I haven't had a chance to mess with it since this morning.

When you say clamp it well, you mean in terms of pressure? Length of time clamped?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Also, must it be spruce? I don't have any at the moment. Would hard maple work?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Just got home and starting messing with it again. I used a clamp to pull the FB support block back toward the neck block. Now, when I run my finger around the inside of the sound hole I don't feel nearly as much, if any, separation at the 2 places it split. I can still see the cracks though. I guess I should fill them with some kind of glue. Don't think I'll get tightbond into a crack that small. I could wick some CA in there but I feel like that won't be strong enough.

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

When I run a straight edge from lower to upper bout on the bass side I see about 1/16" or so of concave dish in the sound hole area. Also, when I run it from treble to bass side perpendicular to the FB extension area, it lays flat on the bass side and there is a slight gap on the treble side. Is that something to be concerned with at this point?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Thanks to everyone for the help and good advice. Guitar is back together and playing great. It has a good amount of room for adjustment in case things drift in the future.

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."