Musicians do various things to support their music-making habits. Some work in bars. Others play in cover bands. (I would shoot myself if I played in a cover band.) I happen to work in the Wanamaker Organ Shop, where we tend to one of the largest pipe organs in the world. I also happen to be one of the assistant organists, so I get to experience two aspects of the activity there.
Maintenance on the organ is made possible through a partnership between Macy’s and the Friends of the Wanamaker Organ, with the generous support of donors. The Friends put out a quarterly newsletter, The Stentor. A while back I wrote an article for this periodical about something that occupies much of my time at work–the construction of Fleming pneumatics, so-named after William Boone Fleming, superintendent of the L.A. Art Organbuilding Company when this instrument was built, and then the first curator when it was installed and expanded in the Wanamaker Department Store in Philadelphia. These pneumatics are leather pouches on a wooden body that depress when a signal is sent to play a note, allowing air into the pipe so that it speaks.
The article begins here:
How many steps are there to building a Fleming pneumatic? I actually have no idea. I’m reminded of the desk sign I read once that said, “Do the next thing.” Sometimes that’s the best approach in what can feel like an endless process, one that is bogged down in one hundred years of history and accumulated detritus. Even something as simple as pneumatic construction is not immune from the interminable debates typical of organbuilding discourse, and there may in fact be better ways of approaching this, but I will describe the procedures currently in place. Whether there are improvements in materials or efficiency, it will always be an involved process, and I thought it might be beneficial for our readership to be aware of the labor intensity involved.
Pneumatics need to be rebuilt every few decades, usually because the leather pouch fails, but the old wooden bodies can be used again, by and large. To do this, the old pneumatics are immersed in extremely hot water so the hide glue holding them together dissolves, allowing the leather and other parts to be removed. This is a filthy job, often performed by several dedicated volunteers. Re-using these old bodies can be problematic, not least because of wide tolerances in size that can even affect valve placement. The good news is that, once finished, they should last for fifty years. Those of us who work here can hope never to rebuild the same pneumatic twice.
Once the old bodies are cleaned, they are ready for sizing and shellacking. The dry rot that affects older wood requires the inside of the pneumatic to be covered in hide glue to seal the pores, while the end grain is naturally porous, hence the shellac. If timed right, these two tasks can be alternated to save time, along with plugging the now-defunct screw adjustment hole, which dates from the time an adjustable spring was used rather than the current high and low pressure designations. The spring hole is also chamfered on the high pressure pneumatics, which keeps moving parts from binding.
Some of the parts used to make a Fleming pneumatic.
A more recent addition is a wooden bridge that strengthens the structure beneath the heel block. On many pneumatics that we’ve been pulling out of the organ, bridges have not yet been installed, so we’ve been busy retrofitting them.
Once all these steps are completed, the wooden body is sanded so there are no sharp points created by either the wood or the hide glue near the pouch, since this could cut the leather and cause the pneumatic to fail prematurely. After this, a felt bumper is added around the spring hole to cushion the pneumatic when it deflates, and then, using a test screw, the screw slots have to be rasped so the pneumatic can be installed properly in the windchest without the slots being too narrow to fit easily around the screws. Anyone who’s had trouble with this in the windchest knows how frustrating it can be.
At this point it’s time to prepare the leather to make the pouches, using the proper templates depending on the size of the pneumatic, and using PVC glue to add the felt and leather valve on the outside and the fiber disc on the inside. These fiber discs also need to be drilled out a bit so the shoe pegs that guide the spring will fit. Then the leather is glued on to the body, first at the top and then at the sides. Various jigs are used to ensure that the valve ultimately sits at the right height. The test of this is that the valve will be higher than the heel block when the pneumatic is finished. These height jigs also help to keep the valve parallel with the body. Excess leather is trimmed, then the springs are installed and held down under weights until the glue dries sufficiently to withstand the tension. The springs themselves can endanger a worker’s sanity. Many are misshapen and uncooperative after several reuses, and others are too small to fit properly in the pneumatic. It is also difficult to tell the difference sometimes between high and low pressure springs, and they are not always clearly labeled.
A leather pouch being glued on with the use of a height jig, with some leather cut away for visibility.
When all this is done, the heel blocks are added. Like the main Fleming bodies, these are re-used, being cleaned in a similar manner. Also like the Fleming bodies, they are highly inconsistent in their proportions, which sometimes makes life interesting when applying them. They are finished with a packing leather gasket that seals against the channel in the windchest that exhausts the pneumatic during operation.
At this point, the leather is sealed with a mixture that is said to be one part RTV silicone and 10 parts naptha, although in practice it may not always be that precise proportion. This helps to preserve the leather and seal the pores in the skin so the pneumatic is more airtight—the number one goal when making them. This solution is difficult to maintain properly over time, so I often let a lot of pneumatics pile up before mixing and applying it.
A few finished pneumatics next to my lunchtime reading for the day, Robert Earl Hardy’s excellent bio of Townes Van Zandt.
Finally, the pneumatic is tested for leaks and labeled. This is no slam-dunk. Pneumatics can be faulty for a variety of reasons, and sometimes the source of a leak cannot be chased down at all. That’s usually when I decide to get lunch.
The construction of these vital parts of the organ is an involved, time-consuming process, probably adding up to two or three man-hours per pneumatic from the time it’s removed until the time it’s returned to the organ—no small amount of time when you multiply by the thousands of pouches that are in this instrument, each operating only one note. In the recent choir restoration, there were a grand total of 798 #1 sized pneumatics required alone, among others. All that work to make one division play! As an organist, I’ve gained a great perspective on what it really takes to make even one note function properly. All the more reason to practice just a little more carefully. The construction process is repetitive and can seem interminable. One of my coworkers visited me at my desk one afternoon and started singing, “99 Bottles of Beer on the Wall.” After I shushed him, he said, “Well, that’s what it’s like to make Flemings.” He’s right, but with enough time and patience, we’ll get them all done, even the ones with the mystery leaks.