Sunday, May 20, 2012

Harmony H1203 Sovereign - Neck Bone Blues

Before putting lacquer on the back and sides, I started working on the neck reset.  All of the work previous to this point was taking a toll on the angle that the neck makes with the top plate, and the top plate is very much out of plane, with some bellying at the bridge and sinking between the neck block and sound hole.

One day, this old guitar might get its top braces removed so the top plate can be flattened out.  That would be a great time to swap out her heavy ladder bracing for an X-braced configuration.  But, for now, I'm letting all that stay the way it is, and just modifying the shape of her dovetail.  I started by cutting some oak shims parallel to the grain with a coping saw.

I attached two small shims to the dovetail tenon cheeks to get started.  After the glue dried, I shaped the rough edges with a file...

... and then with some sanding tools I made from sand paper and popsicle sticks.

When all of the new lacquer on the back and sides had hardened, it was time to get back to the neck reset.  I added and shaped some smaller pine shims where the rest of the joint needed to be filled in.  With repeated dry fitting of the neck into the joint, I shaped the first two shims so that the neck centerline was in line with the centerline of the body and perpendicular to the bridge.

I kept building up the tenon, adding and shaping more small strips, to affect the angle the fretboard makes with the body and end up with the proper string action.

The last few evenings were filled with frustrations, removing too much from the shoulders, and making a few new character marks to her neck.  I realized there will be gaps, but decided to go with it, and attached the last shim to the widest part of the tenon.

Like the rest of the shims, the last one needed a little shaping.

A final check on the centerlines, everything was lining up fine.  Anticipating some rotation of the bridge from string tension, and wanting to allow for some future adjustment, I left about a 1/16" gap between the plane of the tops of the frets and the top of the bridge at the saddle slot.  It was less than I wanted, but it was all I could get, and enough to get the action down low enough by trimming down the saddle.

After the final dry fit, I added some hide glue, clamped up the joint, and called it a day.

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