This is the first Gurian we have worked on. It was unique experience for sure. Just like 95% of the Martins we have worked on, the inside of our Gurian is finished like a piece of fine furniture. Wow, nice workmanship. Obvious tender loving care all over the place.
Our guitar required a reset and some side crack repairs. So the back was removed so as to repair the cracks, but mostly to remove the two ebony pins keeping the neck attached to the body. You really cannot see much by viewing through the sound hole. We know that Gurian necks are held on by two ebony pins. The ebony pins are inserted horizontally thru the side of the neck block and through the neck tenon which is inserted into a mortise in the neck block. See this website for a write up which partially explains the problem of removing and installing these pins. FRETS.COM
Problem is, that article assumes that the Gurian Pin removal tool is available and that the pins are in good shape and that you can see which end of the tapered pins to push out since they can only go out one way.
As things worked out, it may not be necessary to remove the back to access the pins even if they are completely broken off on the sticking-out-end.
Below is an image of the two pins we removed.
The pins are normally 2 inches long and tapered down from 1/4 inch. They are just long enough to go through one side of the neck block then through the neck tenon then maybe a little bit through the other side of the neck block. However, our pins are 1 5/8 inch because the sticking out ends were broken off.
Since this is the only Gurian we have worked on, I cannot guarantee that the following is fool proof. But this procedure seems logical and reasonable.
So which way are the pins removed? What if the pin ends are broken off as they are in the case of our guitar?
Before attempting to remove the pins be sure to unstick the fret board extension first. The neck tenon is not glued into the mortise, so when the pins are removed, the fret board extension is likely to break off as the rest of the neck is free to flop about.
The pins are inserted on opposite ends of the neck block one from the right, one from the left. The fat end of the pin normally sticks out. In our case, they were broken off flush with the side of the neck block. However, on the neck block side opposite from the fat end of the pins is a hole. This is the small end of the tapered pin system. The image below shows our handy dandy pin removal tool.
The above is the cut off end of a 20 penny nail. The 1 5/8 inch length is exactly correct for pushing out the pin, but more importantly, enabling access to the pin with an apppropriately sized pair of pliers. You are working right up against the inside of the upper bout wood so access is very limiting or confined. This pin fits nicely into the pin hole in the neck block and works perfectly to push the pin out.
Pin removal requires pliers with wide opening, deep jaws but with a narrow frame. The pliers are shown below.You might beable to make your own from hard wood.
Milwaukee part number 48-22-3541:
You do not need the compression power implied by these pliers. They are the only pliers I could find having wide and deep enough jaws but also narrow enough to fit through the sound hole. I have not measured these nor verified.
Though I have not proved it or experimented with the following technique, I believe it is possible to slide the these pliers into the sound hole and press the pins out. We did this with the back off and it was easy. The locking pliers shown are the widest available with the deepest reach. Pushing the cut off nail into the open end of the neck block pin hole pushes the pin out easily.
Hopefully, this article is not promising more than it is possible to deliver.
Anyway, we are going to convert this neck assembly to a bolt and threaded insert system.