I need to be able to get glue into the whole joint.
Here we have the spatula covered with glue about to go into the open joint.
Imagine how hard this would be if the neck wasn't clamped up in the amazing guitar vise. I'd be chasing it all over the workbench.
Pressed the joint down, wiped off as much excess glue as I could, and then clamped it up.
The caul under the neck is one I made a while back for just this sort of job. I have a box full of semi-custom cauls now, and it's great to just be able to find one that works without having to make another one.
Two cauls under the neck and one on top, with 2 bar clamps.
You can see the separation after I put the brace jack under the top and raised it a bit to open the seam to get glue into it. You could also use one hand to press open the joint or crack from inside - I've done that - but that's more awkward. With a jack, both hands are freed up to work on the repair.
This is pretty common on older acoustic guitars. It probably causes the owner a lot of consternation, but it's easily repairable. The top was originally made from 2 halves glued together in the middle, and in essence, we're just doing that again.
With the seam opened, I spread hot glue with a brush into the seam. Then I lowered the jack inside the body, and moved it out of the way. The seam mostly closed at that point.
Then I wiped the excess glue off, and clamped the seam flat as you see here.
There's another caul inside the body. Using 2 clamps puts nice even pressure on the joint. I use waxed paper on this kind of repair so the caul doesn't stick to the guitar!
One thing you may notice on spruce tops like these is that the two bookmatched sides look like they're different shades of color - one appears darker than the other. In this picture, the left side looks darker.
That effect is because of the way the grain fibers run - one half of the top runs one direction parallel to the grain, and the other half runs the opposite direction. The way the light is reflected off each side makes one look darker than the other depending on the angle you view it from.
Now that those repairs are done, I can do the calculation for how much material to remove from the heel and get the actual reset started.