3/22/2014 - Banjo Boys - Chapter 31 - Finishing the Cherry Blossom Banjo

Photo courtesy of Mary Ann Mead
Official photographer for the Banjo Boys of Fayetteville

Today, Clint was coming up to the shop to see if he could finish up his cherry blossom-themed banjo.  I hoped to get the holes properly drilled in my maple rim and get my brass hardware installed.  I also had noticed that my heel was too "fat" and exhibited some sandpaper scratches that I needed to eliminate.  We both got partway to our objectives.

Clint started by gluing a split in his dowel stick where he had drilled a longitudinal hole for the endpin to screw into it.  He glued and clamped the split.  This is a very difficult kind of break to repair, since the intercellular bond of the wood has been compromised.  Sure

A typical square dowel stick ferrule

enough, when Clint tried to screw the endpin back into the dowel end, it broke along the glue line.  We discussed the possibilities.  A square-shaped metal jacket, forced over the end of the dowel stick would do the job, but how to bend such a piece with the equipment at hand was a mystery.  It needed to have sharp bends and fit tightly around the perimeter of the dowel stick.  We went back to the drawing board.  What if we could find a tubular brass object of the correct diameter?  Clint could round the square edges of the dowel stick up to a point past the split and force fit it to secure the repair.  We proceeded to the local Ace Hardware store where we found a perfectly-sized brass collar.  Clint cut the threads of one end, smoothed it up, rounded his dowel, drove the collar over the first few inches of the stick, and cut it to the proper length.  The repair was made!

The screws that hold the "shoes"

The shoes, hooks and nuts that
hold the tension hoop

I began the day laying out the pattern for the holes I needed to drill in the maple rim that I had already sanded, stained, oiled, and cut to receive my dowel stick.  I had purchased a pre-notched tension hoop from Rickard Banjos in Canada a few weeks ago.  One of the nice features of a pre-cut hoop is that it provides a guide for the positions of the needed holes.  I centered the string cutout in line with the square hole in the rim into which the dowel stick fits tightly, thinking that that hole represents the center line of the neck.  Then I taped the tension hoop to the wooden rim at a level where the holes needed to be for the hooks to work properly.  This was a little trick suggested by Clint.  I carefully marked each hole location with an awl and then proceeded to drill the holes for the tiny machine screws that anchor each of the so-called shoes.  The shoes are drilled and the hooks extend through this hole and are put under tension by nuts that cover the threaded ends of the hook shaft.  These are held in place by hex-headed brass machine screws extending through the rim.

The ferrule repair

The surprise came when I installed the neck again to check everything, only to discover that my dowel rod is just enough off-center where it enters the nack, that it causes an interference between the side of the heel and one of the shoes.  I'm now in the process of reshaping the heel to make it more narrow, hopefully narrow enough to eliminate the interference.

Clint finished the repair to his dowel stick and it came out fine.  He's going to polish the brass and then antique it using some acid solution he has used previously.  He then shaped the nut that goes at the top of the fretboard, glued it in place, and filed the grooves (slots) that will accommodate the strings.  I think he plans to put strings on it this weekend.  We knocked off early, since Clint had a previous commitment for the afternoon.

The finished maple rim