Restoring the Hardman Studio Wurlitzer

It took the big Mayflower moving van seven days to make the cross-country trip from Hollywood to Great Falls. Because the tractor-trailer was so long, it was unable to negotiate the narrow road through the woods to our home. I rented a 24 foot straight rig to make 11 shuttle trips to the barn from the Mayflower trailer which was parked in a quiet area behind the local Safeway. We remember that as being one very long and tiring day moving all those tons of pipe organ.

All the larger organ parts were initially unloaded through the glass doors and added to the other stuff already being stored in the upper level of the barn which became a makeshift warehouse. The parts to be restored were either carried down the stairway to the shop on the lower level or were taken around to the side of the building and brought in through a rolling garage door providing access to the lower level. Somehow we didn't take many pictures during the long and laborious restoration phase of this project; but these pictures will give you an idea of what it was like during this period of time.

Each pipe box was custom built to fit the particular rank of pipes to be packed. Most of the boxes were 8 ft. long, but some had to be made longer, wider, or thicker to accommodate the longer or larger diameter pipes. Boxes were opened to allow cleaning and straightening of the pipes which were then replaced until needed to place on the windchests near the end of the installation phase.

Restoring an instrument of this size is not a one man job. I had plenty of help from friends and several local musicians who had time available during the day, before their evening gigs got under way. Even so, the restoration phase of the project took about 3-1/2 years. Allen Miller got us started by giving us advice and direction on restoration techniques, with names and descriptions of the materials we would need and their sources of supply.

The tall rectangular box on the left is a dust collecting wire wheel / buffing setup using two HVAC filters to collect dirt and dust. There is an old squirrel cage furnace fan underneath.

Here the treble half of the 49 note Chrysoglott under restoration. A Chrysoglott has nickel plated metal bars and big felt piano hammers that strike the bars. It produces a soft dinner chime-like sound similar to a mellowed-out orchestral Celeste. The long wooden wind chest contains one 3-stage valve train for each note. The valves were removed to replace the tired old leather. The black cylindrical device at the bottom of the photo is a small blower next to its pressure regulator in the wooden box. It was used to provide wind to bench test the various pneumatic actions as they were restored and before the parts were installed in the organ.

Wurlitzer Manual Wind Chest Cross-Section Views
Here are cross sectional views of a typical Wurlitzer valve train for a single pipe. This drawing by Johan Liljencrants shows the successive steps to turn on one of the electro-pneumatic mechanisms in the chest controlling airflow to a single pipe, placed on top. The interior of the windchest is under constant positive wind pressure. When energized, the coil of the electric pilot valve on the bottom board activates a small primary pneumatic amplifier valve. This in turn controls a secondary bellows on the right wall, which forces open the top pallet valve which admits air to the toe of the pipe above. 

This animation by John DeMajo illustrates another way Wurlitzer pipe valves are used to allow wind pressure from the chest interior to enter the toe of smaller pipes.
The Reisner electro-magnetic pilot valve shown above is conceptually the same as those used by Wurlitzer in all their windchests. Some engineering and manufacturing improvements have been made to make the modern devices easier to service and maintain, but functionally they perform exactly as their elder brethren.
Top & bottom boards removed
Keith Taylor is currently restoring his own theater organ in his home workshop in Maine.  He sends me pictures periodically to show the progress he is making during the lengthy releathering process.  This is what the inside of one of his 4 rank manual chests looks like with the top and bottom boards removed. All those little white bellows (called "pneumatics" in the organ trades) will have to be removed, releathered, and reinstalled during the restoration process of the organ. Releathering is not that hard, but it does take a lot of time. It is a very important step in the thorough restoration of any pipe organ to insure long term reliable trouble free operation.

Closeup of windchest as opened Releathering Fixture

The closeup on the left shows what the pneumatics look like in a typical manual chest before being releathered. Each one is removed in turn using a sharp knife to cut through the old leather gasket which separates the pneumatic from the windchest. Keith built the special fixture shown above to help hold the parts in position to make accurate releathering easier and faster for more consistent results. The wooden parts of two common sizes of manual chest pneumatics are shown in place on the fixture, ready to receive their new leather.

A special water soluble adhesive is used in the leathering process. After being removed, the pneumatic is immersed briefly in boiling water to soften the adhesive holding the old leather in place. The old leather falls away from the wood parts and is discarded. Any remaining adhesive is quickly dissolved in the boiling water leaving the wood clean and ready for the next step. The hot wood air-dries quickly and a strip of new leather is cut to the appropriate size and glued on.

New leather during application Ready for reinstallation
After being wrapped and glued in place, the new leather is carefully folded and trained so it will return to that position after the pneumatic is installed and the windchest is placed in service.  On the right is a finished pneumatic, complete with its felt bumper to make silent contact with the pallet valve under the toe of the pipe. A thin leather gasket is used to separate the pneumatic from the wood surface of the windchest.  This makes it easier to remove the pneumatic in the future.

Wurlitzer Offset Windchest Primary Valve Pneumatics Typical Wurlitzer Bottom Board
An offset windchest holds the pipes that are too large to fit on a manual chest. The picture on the left shows an offset chest with its newly releathered primaries. Behind them are the electro- magnetic pilot valves that are triggered from the organ's relay. When activated, the pilot valve causes the primary pneumatic to collapse. Its valve then causes the secondary or power pneumatic to collapse which opens the pallet valve under the pipe toe.  A typical Wurlitzer manual chest bottom board is shown on the right before being restored.  It is about 44" long. The spacing between the primary pneumatics is determined by the physical size of the pipes they will serve.

Maureen Wilkie All our manual windchest bottom boards were releathered by Maureen Wilkie in Buffalo, New York.  Maureen was the perfect choice for restoring these parts since she had gained lots of experience doing the same thing a few years earlier while working with the crew that was restoring the Wurlitzer organ in Shea's Buffalo Theater, now a performing arts center.

I could safely carry just so many bottom boards in my van on any one trip. They had to be carefully loaded to prevent damage to the exposed valve train parts using lots of old pillows and blankets. When Maureen was finished with one vanload, I'd drive another up to her home and bring back her restored pieces.

New leather during application Ready for reinstallation
The releathered power pneumatics have been replaced in this 4-rank windchest. The green felt bumpers will quietly contact the metal levers attached to the pallet valves which are forced open against wind pressure to allow wind to enter the foot of each pipe causing it to sound.

There were many windchests similar to the ones described above that were releathered during the restoration phase of our project here in Virginia. I wish now that we had taken a few pictures of the detailed operations that were performed while releathering over 8,000 pneumatics and pallet valves in the Great Falls Wurlitzer. Fortunately, Keith has been more attentive in documenting his restoration, and will eventually have a website of his own where he can share these and many other pictures describing the history and technical aspects of his installation and its restoration.

On the right are three resonators, standing upside down, from the 16' octave of one of the Tuba ranks. When they were built, Wurlitzer mitered (folded) them making them more compact, and permitting their use in pipe chambers with the limited headroom found in many original theater installations.

With so many pipe boxes in storage around the shop, the place was understandably very cluttered.

A 2-Rank and a 3-Rank windchest are being wired with plug-ended 25-pair telephone cable to allow recalcitrant bottom boards to be moved to the shop for more convenient access to valve train problems should they develop after the windchests have been installed in the crowded pipe chambers.  The valve train operation was described above. Two bottom boards are placed end-to-end for each rank or set of pipes.  Manual chests usually have 61 pipes for each rank, one for each key on the manual keyboards of the console.

A big (and heavy!) 6-Rank manual chest is undergoing final preparations for bench testing under wind pressure to make sure all the pipe valves work properly when the electric signals are applied.

Harold Wright, Brecksville, Ohio, (seated) took responsibility to clean and adjust the reeds in hundreds of the pipes.   Jay Bogart was our Gopher and learned a lot about what it takes to restore and install a big Wurlitzer. He willingly performed a myriad of tasks for us.

Harold is pictured cleaning and polishing a reed before reassembling it with its shallot in that pipe's reed block at the base or foot of each reed pipe in the organ. The smaller reeds are really thin and fragile, requiring great care in handling to avoid bending or folding during the cleaning operation.

Awaiting their turn for restoration are some reed blocks shown inserted into and closing the top of their strong tapered pipe feet. Note the "L" shaped tuning wires, and brass tubes which will receive the long resonators when the pipes are installed on their windchest. The foot of the pipe provides the physical structure to support the weight of the resonator when it sits on the windchest, and serves to protect the fragile reed inside. The boot is easily removed when it's necessary to gain access to the reed, to clean or make adjustments affecting the speech or altering the timbre of the sound produced.

Brian McGuire Rebuilding Hardman Studio Wurlitzer
Brian McGuire plays guitar in a band. His wood working skills enabled him to make many special parts required to adapt some of the organ parts to this installation in Great Falls. He is holding the top of an offset windchest which clearly shows the large pallet valves which control the entry of wind into the large pipes that are too big to fit on a manual chest. The secondary or power pneumatics with old brown leather are still in place in the windchest. They are normally inflated, and collapse when the pipe is to sound. A mechanical linkage will pull the pallet valve open to admit wind into the pipe. The pneumatics will be recovered with white chrome tanned leather.

Box #35 contains the 61 note 8' unison rank for the Wurlitzer Vox Chorus, a 4 rank set of pipes. The other ranks making up the Vox Chorus are a rare 16' rank, an 8' celeste, and a 4' rank.

The concert grand made a convenient place to arrange a rank of pipes by pitch length. Several bottom boards from manual windchests can be seen standing up on the left.

Jay Bogart got tired of cleaning so many pipes! Here he is using steel wool and soap to wash off 90 years of dirt. Each half of the marimba is about 7 feet long. A marimba uses felt-faced wood mallets striking tuned rosewood bars with tunedvresonator tubes underneath. On the left is one half of the 49 note action for the Wurlitzer Marimba, called a Harp on some church organs.

Brian McGuire, Silver Spring, MD, is checking and occasionally resizing the rack board holes which the pipe feet pass through to sit on the top boards of the windchest. This is a 3-Rank manual chest with Concert Flute and Tibia pipes. When all pipes have been mounted, the chest will be test winded from a small pressure regulated wind supply, and every valve train and pipe will be carefully checked to make sure it speaks promptly and with sufficient speed of repetition.

Sometimes you just can't resist giving it a good long honk; but lung power doesn't go very far on a big flute like that one. The handle of the tuning plug is visible on the other end of the pipe.

One of the more frequently used tools in the shop turned out to be the 12" chop saw seen on the left. The console has already been repainted, and the 32 note pedal clavier is about to be rewired so it can plug in to the electronic printed circuit boards inside the console.  It will be painted soon.

The next chapter describes the restoration of the original 4 manual Wurlitzer console.
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