Gulbransen Repairs for Todd & Shannon Kutz

When we made the initial service call to diagnose the problems for the Gulbransen Player Stack and Bottom Unit, we found that it was very hard to foot pump, and with the vacuum running full speed, there was a loss of notes on the high end of the keyboard.  Removing the upper unit from the piano and checking for tightness of the covers and gaskets led to no change.  The tracker tubing was getting hard and several tubes broke when bending the upper part of the stack forward.  We decided that the best option was to bring the upper unit back to the shop for further testing.  The lower unit was tight, so we left that in the piano.  The pictures below show some of the steps in resolving the problem.

Referring again to the above picture shows the three layers of the stack removed from the player and sitting on the bench.  The picture shows numerous valve covers missing.  These were partially loose, and you could just put a fingernail under the edge and pop them loose. 

Most of the loose valve covers showed signs of severe leakage under the loose part for a long time. 


Another example of the leaking covers.  When the player would operate one of the valves with the leaking cover, the force of the rising valve would tilt the cover up, allowing outside air to come into the system.  Over a period of time, this led to the dirty build up as seen in these pictures. As multiple note with the leaking covers were called into play, the vacuum in the upper half of the stack would drop, preventing the notes from playing.
Because of the many loose covers, and the general condition of the valves, it was decided to do a restoration of the pneumatics and valves, and to re-tube the player.
The pneumatics were sheared off after removing the remaining covers and valves and stems.  Because of the general weakness of the glue (Appeared to be watered down hot glue), this did not present any problems.  There were some chips missing, which were filled before covering. Above picture shows board with valve cover and valves removed, and a board with it's pneumatics, showing signature of some prior re-builders.
Two of the 88 pneumatics after removal and repairs to chipped wood.  Note the light area between the pouch well and the opening to the pneumatic.
The three layers of the stack after pneumatic removal and clean-up.  The brass valve seats were also loose, and required removal and cleaning, then re-gluing in place.
Upper part of pneumatics with newly resealed pouch well, and all chips repaired, wait for the shellac on the movable leaf of the pneumatic to dry, and to be hinged.  But first, the new pouches have to be installed and sealed.  Yes, the remote is for my TV,  my connection to the outside world. 
Applying "Fish Glue" to the perimeter of the pouch well lip.  Some re-builders use hot glue for gluing the pouch, but I prefer the fish glue.  It gives you more time to set the pouch, especially if something interesting should come up on the television.
Try to apply the glue to the extreme perimeter to prevent glue from being applied to the portion of the leather pulled into the well as the pouch is dipped.

New leather pouch laid over the glue.


Next I lay a small square of plastic wrap over the pouch.  

Custom sized pouch setter is applied to the pouch.  The plastic wrap prevents seeping glue at the edge from getting on the setting and making a sticky mess.  There are numerous other ways to set a pouch, but on the recessed lip of the Gulbransen, I prefer this method.
After removing the pouch setting tool, you can use the eraser on a pencil to finish smoothing the edge of the pouch if required.  No glue on hand.
Finished, but unsealed pouch.  You may notice that I have enlarged the hole in the end that connects to the tracker bar.  This will be explained in a later step.

Enlarging hole in board to match that enlarged going to the pouch


Enlarged hole and sealed pouch

Small piece of thick wall tracker bar tubing, with one end cut on an angle, inserted and glued into enlarged hole on board, using fish glue.  The angle cut prevents the tube from blocking the opening to the pouch.  After drying, I use a tongue depressor with a slightly larger hole, held over the tubing, and a razor blade to cut it even with the top of the wood of the depressor.  Sorry, I did not get pictures of this step, but will include in the full article on the restoration of the Gulbransen.
Pneumatic slipped over the rubber tubing for test fit.  I put a thin film of hot glue glue on the board, covering three or four pneumatics at a time.  Then apply the glue to the back of one pneumatic, slipping it over the rubber tubing, and aligning with a combination square so it is square with the edge of the board.  Press down firmly with fingers, and go to next pneumatic.  In a warm shop, you can do three or four at a time.  When the glue on the pneumatic hits the glue on the board, they meld together and hold without the need of a spring clamp.
One row down, two to go!  End pneumatics were sealed off in a prior rebuild, resulting in a total of 82 functioning pneumatics.

END