A common obstacle for any guitar tech is fixing bad work from a previous repair. Depending on the situation, working around unorthodox or hastily executed repair work can be the biggest challenge of the job – and sometimes that work is impossible to undo. In this article I’m going to explain why I resorted to making a new bridge for a vintage Martin 0-28 parlor guitar, and how I went about making it.
When this old Martin O-28 parlor guitar came into the shop, the strings were off-center from the neck angle to the point where the client had trouble playing the instrument. Upon further inspection we realized that someone had previously done a neck reset on it, and while neck angle was close, the centerline of the neck was off and the low E was hanging off the side of the neck. The low E string couldn’t be played past the seventh fret! In addition to that, too much of the neck heel was removed during the neck reset, shortening the scale length so that the intonation was too sharp for the guitar to ever pay in tune (unfortunately, I didn’t get a photo of the guitar as it came in, but trust me – it was bad!).
Usually, we’d fix this by doing another neck reset to correct the neck angle and scale length issues; however, we discovered that the last neck reset was done using a two-part epoxy instead of traditional wood glue, which can be melted with heat/steam for manageable removal. But once an epoxy is chemically set, the amount of heat necessary to melt it would completely destroy the guitar!
One alternative would be to cut the neck heel off of the dovetail/neck block with a flush-cut saw and either cut out and rebuild the dovetail joint from scratch, or convert it to a bolt-on neck (like a Taylor or some modern Martin models). This can be a very complicated and therefore very costly – a repair that the client was less inclined to pursue. Another alternative would be to simply remove and relocate the bridge. The problem is Martin does not paint under the footprint of the bridge, so there would be noticeable areas of bare wood on two sides of the bridge. Since he didn’t want to do any finish work to the instrument, we decided on a solution that made everyone happy: making an oversized ebony bridge from scratch that would correct the bridge saddle location without exposing any raw wood.
So here’s what I did:
First, I removed the original bridge with some heat and a palette knife, and plugged the bridge pin holes with some wood dowels.
I’m not much of Martin historian, but I think this guitar was made sometime between 1916-1920. During the boom years of the first Hawaiian craze, Martin was struggling to keep up with demand, so they purchased “Chicago Style” bridges made by Lyon & Healy, which can be identified by the flat, raised wings that set them apart from Martin’s signature pyramid bridges they made outside of those years, until the late ’20s.
First, I cut the ebony blank and sanded it to size, then laid out the bridge pin holes.
Once the bridge pin holes were drilled, I laid out the saddle slot so it would be positioned for proper intonation and put together a very simple router sled to cut the channel.
After the routing was done, I used a half round file to cut the reliefs between the bridge platform and wings.
With the reliefs cut, I used a flat block to sand the beveled edges into the wings.
Starting with 220 grit sandpaper, I worked all the way through to a 5000 grit sanding pad, then the buffing wheels, to put a final polish on the ebony before installation.
I established the new centerline by using a long straight-edge along each side of the neck and measured out the exact scale length to position the new footprint of the bridge. Then I drilled out the new bridge pin holes into the soundboard.
Using modified bridge pins as registration pins in my newly drilled holes, I glued and clamped the bridge into place with Titebond wood glue.
Once the bridge was glued down, I made a new bone saddle from scratch and strung it up with a fresh set of strings. Now, with the strings centered on the neck and the intonation corrected, this guitar begins it’s new life!