Worn Oboe Reed Well

This oboe had a reed well that was too large to accept the standard diameter corks that are on most reed staples. The standard diameter corks are about .270-.275", so the well should be slightly narrower than that, to account for compression of the cork. This well had a diameter of .282", about .010" too large. Every reed I tried just dropped in, so it created no seal and would fall right out. Repairing it meant making a sleeve that was soldered in to reduce the size. 

The first step was to remove the well from the upper joint, where it's held in place with shellac. That meant inserting an expander that's held in the vise, then heating the expander. As the expander gets hot, it warms the well without any danger to the wood of the instrument. The heat releases the shellac so that the well can be pulled out.

A piece of brass rod is drilled out to make the sleeve. This 13/64 drill is exactly the right size for the diameter I needed, so that made things simple. It was drilled to .750" deep, slightly longer than the well.

Next the outside of the rod is turned down to fit inside the well. I needed to reduce the diameter to be .010" smaller, so the walls of the sleeve are .005" thick. When it's that thin, the brass is fragile and difficult to machine, so all the cutting has to be done in one pass. If it's just a few thousandths too large, it's tough to take a second pass to remove that last little bit with destroying the part. 

The sleeve is soldered into the well. Lead free silver bearing solder flows at a high enough temperature that it's unlikely to melt when the well is heated later during reinsertion. It's also what I use for most soldering applications because it's stronger than leaded solder and, you know, lead isn't great.

Once it's soldered in, the sleeve is cut off the rod and the excess is faced off in the lathe.

After some polishing in the bench motor, it's ready to be reinstalled with a little heat and some fresh shellac. The fit was perfect!