BUILDING A WURLITZER 105 BAND ORGAN #9
by Howard Wyman
INSTALLING THE FLOOR PIPES
Of the 97 pipes in the Style 105 Wurlitzer Band Organ, 22 of them are mounted under the floor of the organ. All 22 are stopped flue type pipes and they include the five bass bourdons, nine accompaniment flutes, and the eight largest melody flutes. The remaining six melody flutes are mounted on top of the windchest. In order to fit into the space beneath the floor some of the pipes must be mitered. All five bass pipes require mitering as well as one of the accompaniment flutes. Previously I mentioned that I had arranged the pipes in the positions in which they would be mounted in order to determine where to locate the holes for passage of air through the floor to the pipes. At that time I had not yet mitered the pipes. That was a good time to also check to see if the dimensions for the mitered sections as given in the plan would fit into the space. The pipes will be glued onto leather strips which can be seen in PHOTO A. The leather strip around the air passages serves as a gasket to prevent leaks. By gluing the pipes to the leather they can also be removed later in case they become damaged and need to be replaced or rebuilt. I used hot hide glue to attach the pipes to the leather because it forms a tight bond, yet can be broken apart later with a minimum of damage. As I was building the pipes I had applied a polyurethane finish to protect the pipes. Hot hide glue really needs to be applied to bare wood to hold properly so when I determined the areas on the backs of the pipes that would be glued to the leather I sanded the finish off in that area.
Next came the mitering of the pipes. I had been told by a couple of people who are experienced in pipe construction that a stopped pipe can be mitered with 90 degree angles without affecting the tone whereas an open pipe should have two 45 degree angles to give a less abrupt change in direction. This has to do with the location of the nodes in the air column inside the pipe and I will not go into that subject here. In order to put a 90 degree bend in a pipe it is only necessary to cut through it at a 45 degree angle and then rotate one section 180 degrees. This was not a problem except in the case of the largest pipe, the G bass bourdon. Even when raised as far as it would go the blade in my table saw would not cut the full thickness of the pipe. The band saw would not open wide enough for the pipe to pass through either. I finally ran it through the table saw and then flipped it over, reset my guide and ran it through again. Of course it did not quite match up but using a wide belt sander I was able to dress the cut ends so that they fit together fairly well. To strengthen the joint between the pipe sections I cut a groove into the edges of the angled sides and inserted a spline into the matching grooves when I glued them together.
It was now time to glue the pipes into place. Earlier, in the process of constructing the riser block which contains the air passages from the wind chest to the pipes beneath the floor, the wind chest had been installed. I removed the wind chest so that I could, with assistance, turn the cabinet upside down. PHOTO B shows the pipes after they had been glued in place. The large bass G can be seen on the right, with the bass D next to it. On the far left is the bass C, next to it the bass E, and to the right of that the bass F. Earlier I had been concerned that the handle on the stopper in the bass F pipe might not have enough clearance when the organ was turned upright and I had increased the height of the skirt by 3/4 inch over what the plan calls for. As it turned out there probably would have been sufficient clearance. Now with the floor pipes in place I could set the organ upright again and proceed with the bellows and pneumatic chest.
Editors note: Howard is a retired electrical engineer and lives in Florida. Most of his career was at the Army Night Vision and Electro-Optics Laboratory. He became involved in mechanical music with the purchase of a non-working player piano. As you will see in his articles, Howard is a highly skilled craftsman. Building your own band organ is a real accomplishment and Howard does beautiful work. Howard can be contacted at: firstname.lastname@example.org