This week on the bench is a 2009 Martin OMC-28M Laurence Juber custom artist series. The "M" designation is for Madagascar rosewood back and sides.

 The customer is having issues with the high e string being too close to the edge of the fingerboard . The string is easily pulled off the board and needs to be moved in 1/32".

Martin nut replacements are normally an easy and straightforward repair - just pop out the old nut and make a new one with the proper spacing. This one however, has the nut installed before the finish is applied. The nut is sealed in similar to how Gibson has done it for years.

You can see that the finish has a preexisting adhesion issue between the edges of the nut and the fingerboard. I pulled one of the tuners and tested the finish within the tuner's footprint on the rear of the headstock. The finish happened to soften with acetone, so that tells me it is nitrocellulose lacquer versus a more modern catalyzed finish (note: catalyzed finishes are more difficult to repair seamlessly).

So, back to the nut ...

I took a small brush and carefully painted acetone around the nut to soften the finish. With a sharp new Exacto blade, I scored around the ends of the nut being careful not to cut into the surrounding neck. Where the face of the headstock meets the back edge, I used a thin-kerf saw to cut right up against the nut. Once the finish was relieved, the nut easily tapped out with a maple block and hammer. The nut slot was then cleaned and trued before starting any finish repairs. The area around the edges of the fingerboard were the only areas to chip out as they were already an issue before starting the repair (see photo above). This is an easy fix with a couple drop fills and waiting a week or so before leveling and buffing. Then I can fit the new, properly spaced bone nut.

So this repair is a little more involved than your average nut replacement. Not terribly difficult, but a nut installed pre-finish doubles the work involved to replace it and ties up the instrument for a week or so waiting for the finish repairs to cure.