No Name Mandolin Banjo
I acquired this instrument on eBay. The seller was Vinnie Mondello, one of the world's great banjo restorers. He mainly works on "top of the line" stuff, so this was a little below his radar. See some of Vinnie's incredible work at Vinnie's Place http://www.4stringbanjos.com/Resto.html
It has no identifying marks at all except a cryptic symbol stamped on the inside of the tension hoop. No one that I asked could identify it and even now, it is still a "no name" instrument. I have seen some C.F. Martin made mandolins from the 1920s with identical pegheads and necks and I understand that Martin made some instruments "for the trade" (that is, sold to distributors who put their own label on). If any gentle reads know, I would be delighted to find out the maker.
As shipped, it was missing a few things like hooks and brackets, tone ring, neck attachment hardware, head, bridge, and tailpiece.
Of course, there were some condition issues. The fingerboard was not attached and was warped. The rim cap had been very crudely repaired. The frets were in pretty bad shape. One piece of peghead inlay was missing. The usual dirt and rust. No insurmountable problems so far.
The real problem was the missing tone ring. There were no impressions whatsoever on the top edge of the rim. Normally a hoop style tone ring will leave some impression or at least a rust stain. On the inside of the rim, near the top edge were a series of small hexagonal impressions with a hole in the center:
It seemed clear that the tonering, whatever its configuration, attached to the rim at these hexagonal points. I spent about 6 months looking at every tone ring I could find a picture of with no luck. One day, I bought a pair of old mandolin banjos on eBay and the kind seller threw in a third one. About a month after unpacking it, I looked carefully at the tone ring and there it was! This time the rim had the tone ring fully intact (but rusty). Then it was easy to see how it was made. It was a simple hoop screwed into the rim. There were hex nuts behind each screw so that the tone ring stood about 1/8" away from the rim. The hoop stood about 1/8" above the rim to make an arch top. Simple and easy to replicate.
Moving right along, let's look at what I did. First removed the badly repaired rim cap, which revealed a number of small delaminations in the rim. I repaired them in the usual way: Place a padded C clamp over the delamination and tighten it until the crack closes. Open the clamp slightly and insert cyanoacrylate glue into the crack, and quickly re-tighten the clamp.
Next, I reglued the rim cap but found that it had a small piece about 3/16" wide was missing. I took a small chip of maple, glued it in place, and sanded it to the proper shape. Then I scraped the old, yellowed finish of of the rim and refinished with two coats of clear lacquer. Rub each coat with 0000 steel wool to take off the high gloss.
Now, for the mysterious tone ring. I had some brass stock on hand so I used that. I rolled it into a ring [see my exposition on ring rolling in Part II of the Luxor Tenor article] and silver soldered the ends together. Then I drilled it to match the holes in the rim and screwed it into place with brass wood screws, using brass hex nuts as spacers.
New Tone Ring
Tone Ring Installed
So far, so good. Then I pirated a set of brackets and hooks off other the other mando banjo of the same make, cleaned up the tension hoop, and put a used mylar head on it.
Moving along to the neck. An ugly little mess. First, I disassembled the fingerboard and the underlying laminates using moist heat. I also pulled all the frets at this time and repaired any major chipping due to fret removal. The divots weren't very deep so I was able to sand them out pretty well.
I cleaned up the maple and ebony laminates and glued the stack back together with hide glue. I put a thin shim under the drooping end of the fingerboard so that it would be more or less straight when it dried. It still drooped a tiny bit so I strapped the whole thing, again with a small shim, to a household iron set on "low". After a couple of hours, I turned the iron off and let it all cool in place. Upon removal, the fingerboard was acceptably straight.
Moving along to the peghead, I cleaned and oiled up the tuning machines and made a new Mother Of Pearl inlay for the missing one. I sanded out some scratches and rubbed a couple of drops of orange oil into the rosewood veneer. I scraped the old, yellowed finish off of the neck and gave it a coat of lacquer. Then I added new frets to the fingerboard and glued it in place. Then I gave the neck two more coats of lacquer and screwed the tuning machines into place.
Part II Reassembly
Now it was time to put it all together. Originally, the neck was held to the rim with a brace on the bottom of the dowel stick that screwed into the heel, passed through a hole in the rim, and was capped by a nut that pulled against the rim. I didn't have the brace and I didn't like that system anyway (it pulls asymmetrically on the neck) so I used an ordinary brace from my junk box (visible in the "Tone Ring Installed" photo). I also found a suitable tailpiece and bridge in the junk box.
Upon assembly, the action was too high. ARGH!! Upon disassembly, I drilled a new hole lower in the end of the dowel stick and elongated the dowel stick hole in the rim. This required some minor reshaping of the heel for a good, flush fit. Upon reassemble, things looked pretty good. Here are some "glamour" shots:
I put on a set of GHS Light strings and tuned it up. I've never had a mandolin banjo before. It sounded remarkably like a wooden mandolin. Actually, I thought, a moderately good wooden mandolin. I resold it on eBay for a little over $300.