This Gretsch Synchromatic from 1946 was the first instrument to be dropped off for restoration at the Polo location a while ago. Since then we have been making incremental progress at the Chicago home of Specimen Products while we put the finishing touches on the sanctuary shop.
This guitar was allegedly the first production model with an asymmetrical neck profile. It also carries the rare distinction of having come stock with 5/16” diameter tuning machine posts. A number of the larger arch top instruments from the golden jazz era utilized this format. It is distinctive. It may have been an effort to have the machines not look too dinky on the larger headstocks. Most used Grover Imperials but these are interesting die cast Klusons. The originals are badly corroded from the chemical reactions taking place in the guitar case. Amazingly, I was able to locate exact replacements. The originals can now be quarantined and archived.
The owner of this instrument was told it used to belong to Johnny Cash. I will let somebody else research this premise.
First the neck was steamed out. We discovered the date stamped into the neck block – June 30th, 1946. The sides, top, and back had detached from the block. The whole assembly was loose but in decent condition with very light (too little) glue residue. This was all cleaned, glued and clamped back into precise alignment with aliphatic resin glue.
The neck was then reset to establish a geometry that will accommodate a nice tall floating bridge. The bottom plate of the original bridge is still nicely intact and quite ornamental. Lovely. The original top was barbarically cut down to nothing. I will make another top with the proper height and it will be as right as rain.
The headstock is made with a celluloid overlay that is both beautiful and problematic. An inevitable chemical reaction takes place between the metal plating and the primitive plastic that causes it to crumble and warp. Like an ever growing fungus, the unstoppable rotting of the celluloid twists and delaminates, further accelerating the degenerative process.
The neck inlays are also pearled celluloid and had cupped and shrunk. Each one was carefully removed, flattened, and shimmed up with maple veneer and inlay epoxy. Then leveled and polished. The fingerboard was then planed flat and re-fretted with jumbo wire.
To revive the headstock, I chemically melt the whole assembly and recompress it flat, similar to the way that the original sheet stock from which it was made is formed. This gives us another shot at life, albeit one still doomed to eventual disintegration, as always.
Nitrocellulose is a funny material. It is only vaguely removed from actual nature. Pretty raw stuff. Like a pile of leaves glued together.
After tracing the inlay, I recut the entire Synchromatic logo out of white celluloid sheet. I then excerpted portions of it to replace the most degraded and missing portions of the original. Thorough removal of all the decomposing celluloid was meticulously carried out using picks and tiny chisels.
The new inlays were then fit into place with a slurry of heavy liquid celluloid made from slivers of tortoiseshell binding dissolved in acetone. The pieces are set down into this slurry and crevices are filled in. Several days are then needed for drying, evaporating, and shrinking.
Many laps are required, repeating the process of sanding, spraying and drop filling the head plate to bring the surface up to something that can be leveled and polished. With patience and perseverance, dignity can be restored to this forlorn soul.
