The mouthpiece will be placed in the small end of the tube. In order to provide the shank of the mouthpiece with a strong and airtight fitting, a receiver needs to be formed inside the tube.

A 1/2" dowel was used as the inner jig for the small end of the tube, since the appropriate receiver diameter is also 1/2". The receiver must be round, inside the square tube. The method used on the prototype is as follows.

After gluing the tube, the dowel is removed. Left over fine sawdust, preferably from the rabbet routing operations earlier, is mixed with 5-minute epoxy. Use about a 50/50 ratio between epoxy and sawdust. 

Mark the dowel at a point 1/2" from one end. Liberally coat this much of the dowel with the epoxy-wood mixture, then work the coated dowel into the tube up to the mark. Use a flat screwdriver blade, knife blade, etc., to pack more epoxy into the spaces around the dowel; try to imagine how much is needed to completely fill all empty spaces from the end of the tube to the end of the dowel.

Allow the epoxy to cure completely.
 
 

 
Saw off the very end of the tube, taking off about 1/16" of the plywood and all but the inserted 1/2" of dowel.

Note in the photo that the small end of the prototype tube was not properly tightened around the dowel during the original gluing process, as there are gaps in the rabbet joints. The extra epoxy that was packed in has filled these gaps.

 
Bore out the dowel, using a 1/2" bit. It is advisable to first drill a small pilot hole in the dowel, to guide the larger bit and keep it centered. 

In the photo, it is obvious that the drill deviated slightly from center, leaving a small amount of the dowel. There was no way to correct this without either making the hole too large, or making it oblong in shape. It worked out fine as shown.

This receiver will accept either a modern mouthpiece from a trombone, baritone or euphonium. It will also accept most authentic or reproduction serpent mouthpieces.

Serpent mouthpieces usually have very short shanks, and they will end close to where the receiver ends; a good fit! Modern mouthpieces have much longer shanks, and they will extend well past the end of the receiver. If a modern mouthpiece is expendable, try cutting off the extra shank.

Always insert the mouthpiece shank into the receiver with a firm twisting motion, in order to achieve an airtight seal.

All photos made using a Kodak DC240 digital camera.
 
 

Go to next chapter