Bacon mandolin repair

Q: Hello from Australia Steve,
I have a Bacon Belmont mandolin, probably dating from 40s or early 50s. The centrew top seam has split, cleanly, and the back is starting to separate from the sides. My intention was to remove the back, glue and cleat the top and the replace the back after first making some sort of jig to hold everything square. Does that sound okay so far?

But here's the tricky bit. These mandos have parallel bracing. Exactly parallel, each brace about 1" out from the centre, running the full length of the mandolin, and HUGE. Each brace is about 3/8" wide and about 3/4" deep. I'm tempted to remove the braces while the back's off, thin them down and brace it like a Gibson A-50. However, if I do that, I'll lose the Bacon's own character, and make it into a Gibson under another name. If I don't, I suspect the huge braces will kill any tone.

What would you do?
Thank you for your help.
David

A: Dear David,
The top seam has opened because the top has shrunk with age. It must be closed by, somehow, making the top bigger. Hanging it over a steaming bath tub can do wonders, but if that doesn't work you will have to add some wood; to the crack or to the edge, either way, removing the back won't do the job. Are you familiar with luthiers clamps or "through pull" clamps? They are L shaped pieces of wood with a guitar tuner mounted on the upright side and a small hole in the foot. You run an E string through the tuner, through the hole, through the crack, through a cleat, through a caul, and then loop the string through a string ball to tie it off. You slap some glue on the cleat and tighten the string with the tuner. Leave enough slack string on the inside to make it easy to pull out after the cleat is dry. If you use multiple luthiers clamps, be sure that you don't get slack string from one patch under the next patch. Most centerlines that I have dealt with will steam closed. Then, I clamp them gently across the top and cleat them with clamps through the sound hole or luthiers clamps. Let it dry, mess with the finish and your done.

The braces are another problem. It would be logical to fix the top and then string it up and listen to it. If it sounds great, you are done. If it is thin or tinny, attacking the braces will help. You will need the back off to deal with the braces. Check for the grain alignment and the fit and tightness of the joints on the old braces. If they pass inspection, take a sharp chisel and reshape them. 3/8" wide is fine, but I would cut them down to a half inch under the bridge and then taper them to nothing at the ends. If they are loose or crappy go ahead and replace them. Recently we have gone hog wild with replacing braces. We X braced an old Washburn Parlor guitar and X braced an old flat back mandolin. I've even X braced an old flat back Harmony. They always sound much better and richer but they never change as much as you expect them to.

Steve Mason

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