Replacing Player Piano Gaskets

Some worn out and leaky leather gaskets.

This post is part of the Milton Player Piano Series.

When dealing with an underperforming player piano, one of the likely culprits is worn out leather gaskets. There can be dozens of these types of gaskets inside of a player piano action and a small leak in each of them can accumulate to the point where the person pumping the pedals has to pump unreasonably hard or fast in order to compensate. When taking apart the player action and bellows, look for leather gaskets with large cracks, missing pieces, and black edges. These are the gaskets that need to be replaced. Also, you might as well replace any other old gaskets that you come across while you have the system disassembled.

Note the cracks in the leather and the black, burnt-looking edges.

There are a few different materials that can be used to make these gaskets. The best material to use is a fine quality suede calf skin leather, however most hobbyists wont have access to leather that has a consistent enough thickness and compressibility for this job. It is much easier to find and use sheets of neoprene to make new gaskets. Cork is also available, which is more durable than neoprene and easier to shape, but offers less compressibility. For this job, I will be using neoprene from http://www.player-care.com/gaskets.html

A roll of neoprene gasket material.

Once you have separated the two gasketed pieces, mark the outside edges of the old gasket with an awl, and proceed to scrape the leather gasket off of the board. I use a razor blade to remove the majority of the leather without damaging the wood. Next, sand any remaining leather or glue residue with a sanding block until you are left with bare wood. Gently vacuum any wood or leather dust out of the chambers of the bellows or player action.

After scraping with a razor blade.

Smooth the board out with a sanding block.

Cut four strips of neoprene so that they make a neat rectangle where the old gasket used to be. They must fit tightly together and not allow any air to leak through the seams. The compression of the neoprene will help with this a bit, but try not to rely on it. Make your gasket as tight fitting as you possibly can. Make small pencil marks on the board wherever there is a screw hole, so that you will know where to punch holes in your gasket later.

Make sure that the smoother edge is the one that will be in contact with the rest of the gasket.

Applying PVC-E glue to the gasket.

Once your pieces of neoprene are cut, apply PVC-E glue to the bottoms of them and press them into place on the board. After the glue has dried, do any trimming you need to do with a razor blade, and punch out the screw holes with whatever small metal tube you have around. I used the back end of a small brush.

Note the pencil marks on the wood that indicate the location of the screw holes.

The ends of the top and bottom pieces of the gasket have been trimmed flush.

Cutting out the screw holes with the back end of a brush.

Push the screws through the board to clean out any glue residue, screw the two boards together, and test out the gasket by listening for any air leaks while the bellows are being worked (or by attaching to a vacuum pump).

Ready to reassemble.

Testing the gasket by taping over the other holes in the board.

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Repairing Player Piano Rolls

This post is a continuation of the Milton Player Piano Series.

While not technically part of a player piano, the music roll is still a vital component of the operation of the player mechanism, and if there are problems with the music roll, there will be problems with the performance of the piano. These rolls are very delicate and can be heavily damaged in the blink of an eye by a player piano that is no longer functioning optimally. Fortunately, they can be repaired quite easily.

The music roll attaches on the left side. The bolt at the top is tightened slightly to hold the roll in place.

For this job, you want to use the highest quality tape that you can. Archival or book repair tape is good. Otherwise, Scotch Magic tape will work in a pinch. The most important tool for this job is the roll-repair jig. This is basically a flat board about 3 feet long with two pins or bolts on one end to hold a music roll, and a wooden rod on the other end to act as a take-up spool. Both ends should be suspended an inch or two above the board to allow the rolls to spin.

The music roll in place.

The take-up spool.

Once the jig is built, load up a damaged music roll, pull the tab across and hook it onto the take-up spool. The roll can now be slowly pulled across the board, repairs made where necessary, and the roll rewound by hand. I place a couple of rulers on top to hold the paper against the board in the middle.

The music roll attached to the take-up spool.

When repairing a tear in the roll, first unfold any bits of paper that have become folded under or creased. Usually all of the paper is still there and attached. Sometimes there will be tiny tears and folds that are hard to straighten out with your fingers. Keep a small screwdriver or awl handy to straighten these out. Once the paper is straightened and in place, carefully tape over the tears. I always place my tape along the length of the paper, never across the paper. I do it this way because during play, the paper is placed under tension along its length and placing the tape this way serves to strengthen the paper moreso than taping across the paper. If there are pieces of paper missing that you have taped over, place tape on the underside as well. This will prevent the exposed sticky side of the tape from contacting the paper underneath when it is rolled up.

For tape that is placed along the edge of the roll, make sure that the tape is flush with the edge of the paper.  If the tape hangs over the edge a bit, trim it flush with a ruler and a razor blade.

The tape has covered up some of the note-playing holes.

If any of the note-playing holes have been covered by tape, carefully cut them out with a razor blade or pen knife.

Note-holes cut out.

Before loading the roll up and testing it, make sure your player piano is properly adjusted and wont just tear it again.

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Re-Tubing a Tracker Bar

The upper stack of a player piano after replacing the lead tubing with new rubber tubing.

One of the more delicate parts of a player piano system is the series of small tubes connecting the tracker bar to the valves. The tracker bar is the brass bar in the top-center that “reads” the holes in the music rolls.

The tracker bar

When the pedals of a player piano are pumped, a vacuum is created inside the body of the system (aka the “valve chest”). This is where the valves are located. The vacuum also continues up through all of the tubes and into the tracker bar. When a hole in the music roll passes over the tracker bar, air is pulled into the corresponding tube which directs it to the “pouch board”. The pouch then operates the corresponding valve (which plays a specific note on the piano). In most old player pianos, these tubes are made of lead. Yes, that heavy, toxic metal that you hear so many bad things about. While lead is not harmful as long as it isn't disturbed, it can oxidize over time. This causes problems in player pianos because as the inside of the lead tubing oxidizes, it creates small, dusty particles that get pulled into the valve chest and can interfere with the action of the valves. This lead oxide can also be harmful if it is inhaled. Be sure to wear a lead-approved respirator as well as gloves while handling lead tubing. It is impossible to tell from the outside if the lead is oxidizing or not, because the outside of the lead tubing will be coated with shellac in most pianos, preventing its oxidation. The only way to tell if there is a problem is to cut open one of the tubes and look inside. If there is no powdery substance inside, simply splice the tube back together with a small piece of rubber tubing. If there is oxidation inside, the tubing should all be replaced.

For more information about the danger of lead tubing, take a look here: http://www.player-care.com/lead_tubing.html.

Before starting, order your new rubber tubing. You can get it here: http://www.player-care.com/tubing.html. Standard tracker bar tubing is 9/64” Inside Diameter. You will need at least 100 feet to re-tube an entire tracker bar. While you are at it, order 100 straight brass connectors for 9/64” ID tubing as well. You will need these later.

You will need to remove the upper stack (this is the assembly that sits on top of the keyboard and is comprised of the valve chest, striker pneumatics, and spoolbox). On Standard-type player actions, this is held in place by one large vertical screw on the right side and four medium-sized horizontal screws on the left. After removing these, the player action can be slid toward the front of the piano and lifted out. Rotate it 180 degrees and set it on a sturdy workbench. Before cutting anything, make note of any tubing that connects to any other devices. There will usually be a few tubes connecting to the tracker pneumatic on the left side (if viewed from the front). Make a drawing of where these tubes connect on each end, as they need to be re-tubed in the same order.

The tracking pneumatic. Before cutting the lead tubing, be sure to make a diagram of all tubes and where they connect on each end.

Using a shears, cut through the center of all of the lead tubing. The tubing is probably cemented directly into the pouch board. You will need to remove the tubing from the board. This is usually easy to do after the cement around the tube has been chipped away. Just gently grab the tube with a pliers and twist it back and forth until it comes free. If the tube breaks off, turn a screw into the center of the tube and use that to pull out the stump. To remove the tubing from the tracker bar, separate the tracker bar from the spoolbox by removing the two machine screws from each side. Soak the tracker bar in kerosene for a day or two until the tubing has softened enough to be scraped off. Give the tracker bar a good polishing with 0000 steel wool while you have it out.

The removed tracker bar ready for cleaning.

The backside of the spoolbox after removing the tracker bar. Notice the holes in the pouch board at the bottom of the photo where the lead tubing has been removed from.

While the tracker bar is soaking, the holes in the pouch board need to be modified. The new tubing cant be cemented directly into the board like the old tubing. Instead, the straight brass connectors that you bought are going to be glued into the board with burnt shellac. Burnt shellac can be made by buying a can of clear shellac from any hardware store, pouring about a cup into an old steel pot and igniting it. The alcohol will slowly burn off and the shellac will become thicker. Put out the flame by putting a lid on the pot after about 5 minutes. Let the shellac cool and then test the consistency. It should be about as thick as Elmer's Glue. If it is not thick enough, burn off some more alcohol. If it is too thick, add a bit of denatured alcohol. Burnt shellac will create an airtight seal, will stick to just about anything, and can be easily removed with alcohol. It also takes a very long time to set (sometimes up to a week).

New brass connectors.

The pouch board removed from the upper stack.

The brass connecters are slightly smaller diameter than the lead tubing that was glued into the pouch board, so the holes need to be plugged and re-drilled with the correct size drill bit. To plug the holes, first separate the pouch board from the upper stack by removing all of the screws going through the face of it, then clean any remaining bits of glue or tubing from the holes where the tubing was inserted. Keep track of which screw was where by finger tightening each screw into its correct hole in the upper stack after the board has been removed. Next, cut 88 1-inch-long pieces of wood dowel that will fit snugly into the holes. The proper size for me was 3/16”. Normally when plugging holes, I use plugs that have the grain running horizontally across the plug so that screws wont slice through them. In this case, we are just gluing brass tubes into the holes, so the orientation of the grain doesn't matter, and we can use dowels which have the grain running the length of the dowel. Use any wood glue to glue the dowel pieces into each of the pouch board holes. Push the dowel in about halfway. Once the glue for all of the dowels has set, use a fine toothed saw to cut them flush with the top of the board.

Wood dowels.

Dowel glued into the pouch board.

Dowel cut off.

Waiting for glue to dry.

Flush cutting the dowels.

Pouch board after plugging holes.

Use a 5/32” brad point drill bit to drill a hole through the center of each dowel. Drill as vertically as possible. Dump out any wood scraps in the hole, and gently blow each one out with compressed air. Using a small brush, paint a bit of burnt shellac onto the side of a brass connector. Twist the connector while pushing it into the board so that the shellac makes a collar around the connector. Push the connector about halfway into the board. Repeat this with the rest of the holes. At this point you can set this board aside for at least a few days while the shellac hardens.

Plug after drilling and inserting a brass connector.

Applying a drop of burnt shellac to the side of the brass connector.

Spin the connector into the pouch board to create a collar of burnt shellac.

Set the board aside for a week to allow the shellac to dry.

When the shellac is hard, re-attach the pouch board to the player action. The next step is to rough cut all of the rubber tubing to go from the tracker bar to the pouch board. Remove the tracker bar from the spoolbox by loosening the four machine screws from either side. The length of tubing can be estimated by holding one end in the approximate location inside the spoolbox and loosely running the other end to the correct brass connector. Be sure to leave some extra slack just in case. Cut the tubing, dip one end in a lubricant, and slide it onto the proper brass nipple on the back of the tracker bar. Make your way through all of the tracker bar nipples, making sure not to loose track of which connector you are measuring to. Cut the four pieces of tubing for the tracking pneumatic as well, following the drawing you made earlier. Attach these to the tracker bar.

Estimating the length of a piece of tubing.

Lubricating one end of the tubing.

Pushing the tubing onto the tracker bar nipple.

Using a razor blade to keep track of which brass connector I am measuring to.

The tracker bar halfway tubed.

Tracker bar fully tubed (except for the two on the left which will lead to the tracking pneumatic).

The tracker bar can now be reattached to the spoolbox. You may need to remove the thin panel in the back of the spoolbox to be able to insert the tracker bar from the back. Reinstall the panel after the tracker bar is reattached. Start sliding the free ends of the tubing over the brass connectors. Take your time and make sure that each tube is connected in the correct place. Use a flashlight and look at the back side of the tracker bar to be sure you have the next tube in line. If you have too much slack in a tube, cut it down a bit so that all of the tubes look clean and organized.

Pouch board re-attached.

Spoolbox back-board removed for easier installation of tracker bar.

Tracker bar tubing coming out of the back of the spoolbox.

Spoolbox back-board reattached.

Attaching the tracker bar tubing to the brass connectors. Make sure the correct tube is being connected.

Keeping the tracker bar tidy after it has been attached to the brass connectors.

After all of the tubing has been attached to its brass connector, reinstall the player action and give it a test.

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Replacing Player Piano Pouches

This post is a continuation of the Milton Player Piano Series.

A dissembled player piano action showing from the top to the bottom: pneumatics, primary valves, and the leather pouches that activate them. Note the hole in the pouch at the bottom center of the photo.

A damaged leather pouch.

In my last player piano post, I described the procedure of cleaning the valves that direct the flow of air and vacuum inside the player action. This time, I am replacing several of the small leather pouches that control the valves. The leather on these pouches is pretty well protected inside the valve chest, but it is very thin and vulnerable to any debris that gets sucked into the action.

My player piano had one missing pouch and two damaged ones. I purchase my replacement pouch leather from Schaff Piano Supply. I believe that the smallest amount that you can purchase is 7 sq. feet which is enough to replace all of the pouches in the action.

In their resting state, the pouches are “deflated.” When a music roll is played, air is allowed underneath the pouch which causes is to “inflate” and push on the wooden buttons that I mentioned in my post “Cleaning Player Piano Valves”. For the pouches to inflate properly, they must be airtight and have the correct amount of “dish” or concavity.

The first thing to do is to carefully remove the old pouch with a razor blade. If you are only replacing a few pouches, be careful not to damage any their neighbors. If more than a couple are damaged or are no longer airtight, it is a good idea to remove and replace all of the pouches.

The "pouch well" can be seen after removing the leather.

Find a round object that is the same size as the old pouches. This will be your template to trace out the new pouches. I used the inside diameter of a roll of electrical tape. Trace the template onto your pouch leather and cut it out with a scissors.

Using a brush, apply a small amount of liquid hide glue to the edge of the pouch well. Wrap the glossy side of the leather around a coin and drop it into the well. It important that the matte side of the leather is against the wood, as the glossy side will not adhere as well. Use your finger to smooth the pouch leather outward and against the wood. If you are replacing all of the pouches, it can be a good idea to purchase a vacuum-operated pouch tool. This tool ensures that each pouch is given the perfect and exact same amount of dish.

A small amount of hide glue applied to the outside of the pouch well.

The new pouch leather dropped into the well.

Allow the hide glue to dry for 24 hours before testing the player action.

The pouch after smoothing the edges.

The replaced pouch.

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Cleaning Player Piano Valves

This post is a continuation of the Milton Player Piano Series.

I've been working my way through all of the valves by removing, cleaning, and resealing them.  These are the valves that translate the small openings in player piano sheet music into the striking of the appropriate strings.  Behind each valve is a small pneumatic that, when the valve is closed, the pneumatic has air in it and does not actuate any other parts.  When the valve is open, the pneumatic is exposed to suction which causes it to close and launch the hammer toward strings.

The valves are meant to be airtight, but since the valves are exposed to small particles in the air that are pulled through the player action, it is possible for the sealing surfaces to catch some dust that will cause them to no longer be airtight.  The valves only move about 1/32 of an inch between the open position and the closed position, so even the smallest interference can cause the valve to malfunction.   I have no idea when the last time this player piano was serviced, but there was plenty of air leakage in the action, so I decided to go through and clean the valves. 

 This piano actually contains a double-valve action.  Each note uses two different valves.  The second set of valves can be seen in the photo below.

In this post, I am focusing on the lower set of valves.

The first step is to remove the wooden button that is threaded onto the end of the valve stem.  I use a set of Kelly Forceps to grasp the valve stem while I unthread the button by hand.

Remove the four screws holding the faceplate and set them aside in a way that you will remember which screw belongs in which hole.

The next step is to loosen the glue that is holding the valve to the board.  I do this by heating up the faceplate with a soldering iron.  Hold the iron against each side of the faceplate for 20 seconds to heat it up enough to soften the adhesive.

In order to remove the valve withough damaging the wood behind it, I use a Park Tools Pin Spanner.  The pins fit nicely into the screwholes in the faceplate and allow me to rotate the faceplate in order to break it free from the hold of the glue.

After the glue looses its hold, carefully pull out the valve and separate the faceplate, stem, and leather disc.

Note the guide in the center of the recess.  The back end of the valve stem fits into this guide to ensure it moves smoothly.

Using an old toothbrush, gently scrub the leather disc on the valve stem, as well as the loose leather disc.  Try to remove any traces of dust or dirt.

Additionally, clean any old glue off the back of the faceplate.  A clean surface here is important for a good seal against the wood.  I use a single edge razor blade to scrape it clean.

To reseal the valve to the board, use burnt shellac.  This is simply a thickened form of shellac that you can produce by buying clear shellac from the hardware store and burning off some of the alcohol in it.  Burnt shellac is an amazing adhesive.  It sticks to almost anything and it does a great job when something needs to be airtight.  The only downside is that it can take a week or longer to fully cure, so don't use it for any last minute repairs.

Brush a layer of burnt shellac around the edge of the valve socket.

Reinsert the valve.  Make sure the valve goes in straight, and the end of the valve stem fits into the guide inside the socket.

Reinstall the screws.  Be careful not to overtighten these screws and strip out the threads in the wood.

Finally, reinstall the wooden button.

Now repeat 87 more times!

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