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A 1973 Gurian
"Pinned Mortise" Reset
© Frank Ford, 9/20/02; Photos by FF

This article is doesn't show the complete job, so if you'd like more details on the reset procedure, check out some of the Martin neck resetting articles listed on the Big Index Page.
Starting out as a classical guitar maker, Michael Gurian built his first steel string guitars with the traditional "Spanish heel" construction, in which the neck is integral with the body. Very soon, though, he switched to a removable neck style of construction. This example is a large fingerstyle guitar made in 1973, with Brazilian rosewood back and sides. Now that it's almost 30 years old, it shows the typical body changes brought on by time and string tension, so it's time to reset its neck.
From about 1972 until the company's demise in 1981, Gurian guitars were made with a mortise and tenon neck joint. The neck tenon was not glued into the body, but was secured by two ebony tapered pins, driven in from opposite sides of the neck block. You can see the lower one clearly in this photo.
By reaching inside, gripping the pin with my diagonal cutter, and prying against the edge of the neck block, I can pull the pins out.
Here's one. It's a turned ebony pin, which matches up to a tapered hole drilled sideways through the neck block.
I have to heat the end of the fingerboard to weaken the glue so I can release it from the top.
The fingerboard came off neatly, and the neck slipped right out of its mortise. Gurian was one of the first factories to recognize the need for neck resetting and accommodated it with a nice removable joint.
With the neck out, it's easy to see the holes. Notice the truss rod, angled downward so the nut will be easy to reach with a wrench. That was a good way to avoid having to drill an access hole in the brace under the end of the fingerboard.
The first thing I do, whenever possible, is remove the truss rod nut and apply some white lithium grease or other good lubricant. That way I won't forget to do it as I go along with other repairs. Lubrication sometimes makes the difference between an easily adjusted rod and a broken one!
Here's the whole thing, mortise, tenon and pins.
I proceed with the neck resetting as I would when working with a dovetail, first "roughing" with a chisel to remove material from the lower portion of the heel.
Then, with the neck placed in position, I'll pull sandpaper through the joint to even out the fit and make tiny adjustments in each dimension. For more detail on this operation, check out the Martin resetting articles on FRETS.COM.
If I put the pins back in the neck to hold it in place, the heel stands away from the body by the exact amount that I removed from the heel. I then look around to find a piece of fiber board that's the same thickness as the space at the end of the heel. Here I found a piece that's .030" thick, and it's tight fit.
When I dunk the fiber into some boiling water, it becomes pliable almost immediately. By the way, these days Michael Gurian is a manufacturer of purfling, bridge pins and things for guitar makers. He's my supplier for this fiber material. It's the stuff he uses for black lines in many of his purflings.
I wrap a piece of the limp fiber around the thin end of each pin.
And wind it up with some string.
After it dries, I have a pair of great little sleeves I can use as a bushing in the mortise holes.
In it goes with some glue, with the open side of the sleeve facing in the direction of the peghead. This sleeve will be my shim to pull the mortise joint up tight as I replace the pins in position.
Here it is, leveled and ready to trim.
My tapered reamer has teeth only on half of its diameter.
Working back and forth in an oscillating motion, I can cut only one side of the hole.
That way, I end up with a nice crescent fill that will be a good fit for the pin, and provide the extra pull necessary to draw the neck tight against the body. I treat both holes the same, but cutting a bit more away on the upper one because its position changes only half as much as the lower.
Years ago, when Gryphon was a Gurian dealership, Michael Gurian sent us this pair of pincers he made for the purpose of installing the pins.
There's a nice recess in the end of the jaw so it won't slip off the pin.
A good hard squeeze, and the neck is back in place, drawn up tight against the body. While it's handy to have the "real" tool, a simple block of lead can be used to drive the pins in just as well. It's tough to swing a mallet in there! From here, I can reglue the fingerboard, and the reset is done.

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