Friday, March 15, 2013

Gibson Archtop Part 2

There are some places where the kerfed lining is missing.  These are the greatest little clamps. I found them one day at the dollar store, six in a package. I used to use clothespins wrapped in rubber bands, but on triangular binding like this if one doesn't get the placement just right they tend to pull the lining strip up. These things have swiveling pads. Rotate the inner pad out of the way and there's a little notch that keeps everything exactly in position.

Here's a little opening where the top is lifting. I used a palette knife to get the hide glue in there and clamped it in place with spool clamps.
The back was installed in the same manner. I know I'm going to put a coat of spirit varnish over the sides, otherwise I'd be more careful and  use short lengths of drinking straw over the threaded rod to be certain it doesn't scratch up the surface.  The back went on pretty well. There's one area in the upper bout that must have shrunk some across its width, or the sides have sprung a little. It's just shy of a perfect fit.
The binding is quite narrow. I used my veneer scraping tool to shave a little off the height to keep it from tipping inwards during installation.
This is ABS plastic. (The original is celluloid). I picked up on a trick from John Calkin and the crew at Huss and Dalton who use Tightbond glue to secure plastic bindings. Roughing up the inner surface with 80x sandpaper provides enough tooth for good mechanical adhesion. (Better than you'd imagine). It cleans up much more easily than the solvent based plastic glues - they have a tendency to liquify the surrounding finish. This old lacquer is crazed and chippy. Low-tack tape is a must!
The missing tailpiece string retainer had me scratching my head. I found some photos of various original designs. Perhaps the original was made of nickle-plated brass. In the end I decided to fabricate it from aluminum bar stock.  My first attempts with a 1/16" drill ended in failure. Too much heat and friction and the bits kept breaking off in the aluminum.  I beefed up the hole diameter and used a countersink on each side to provide a soft transition for the string.
Smooth radius to prevent string breakage and a place for the ball-end of the strings to sit.
I resisted the urge to buff it up to a mirror shine. It'll do the job and it doesn't call attention to itself.

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