Restoration of a Foster Pratt-Read Player Piano for Robert and Kris Lukowski
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31) There was a board that capped off the top of the back
frame. It's glue joints had failed all around the edges but the center area was
still holding a bit. Never the less, it came off with very little trouble. All
these boards whose glue joints have failed are going to have moisture contents which are
too high and will have to be kiln dried and then stabilized before they can be glued back
together. Actually, my suggestion is going to be to let me replace the back frame
(which is damp and made from soft woods like pine and spruce) with the a much harder and
more stable wood, Black Locust. Although most high end pianos use Sugar Maple (AKA
Hard Maple, AKA Rock Maple) to build their frames and to make up their bridges, Black
Locust has a higher level of hardness and stability than Maple does. It is not
generally used because it is hard on tools, difficult to work with, more rare to find and
more costly for factories to put into use. All the qualities of Black Locust will
add strength to the system that surpasses even that which is normally thought of as top of
the line. Also, since the old wood was glued together with hide glue, it would be a
very bad idea to glue it back together again with anything but hide glue again. The
old glue could be removed as much as possible by soaking it and the new glue would bind
with the old; creating the best joint available if we were to retain the old wood.
With a new back frame of Black Locust, I can use glue such as epoxy which is impervious to
moisture thus putting an end to this problem permanently. What's more, I would build
the replacement frame in such a way that the entire system was built so that the structure
locked together throughout. The holding of the string tension and the retention of
the sound board would be improved by having the frame built so that it locks together.
Even if the adhesives were to fail, the design of the frame would hold it together
strongly for an indefinite period of time. The new back frame would even be strong
and stable enough to survive total immersion from a flood without the structure failing.
32) This is a photo of the pressure bar which holds the strings
tight against the metal lip that terminates the speaking length of the string on the
plate. This has been subjected to so much moisture that I ruined every screw getting
them out and had to use extreme measures to remove the two screws that are still down in
this photo.
33) The strings have been measured for future restringing reference and the
tuning pins are being removed. The pins came out hard because they were so loose in
their holes that it was hard to get them to back out so that I could get hold of them to
lift them out. This pianos appears to have been treated with glycerin at some stage
in its life to try to tighten the wood around the tuning pins. There are wooden
bushings which help unify the pin block (the hard laminated wood block that the tuning
pins are driven into) and the plate. Since you will shortly see that they did not
make this plate with a lip in the casting to help hold the tension of the strings as most
other pianos do, these bushings are all we have to rely upon to unify the system and
transfer the tension equally between the plate and the back frame.
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34) This is a separate piece of casting that you saw in
previous photos of the plate. It is a cosmetic (basically) component that hides the
pin block. It also holds the one decal we've seen as such a large file. Since
the decal was on this removable piece, I was able to take it to the office and scan the
decal at 600 dpi. It's condition is still so bad that trying to make a replacement
is fairly pointless.
35) The tuning pins are out. The dark color of the plate
bushings (which are made of hard maple) are proof that they were treated with glycerin
years ago.
36) A wide shot of the piano before the plate was removed but all other
components are out.
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37) A photo of the back frame. It takes a careful eye
to see the condition of the joints. But this will help you understand the situation.
When the back frame is in good condition, you can't knock it apart with a sledge
hammer. The glue would hold even if the wood finally failed from the hammer blows.
This frame comes apart with the greatest of ease.
38) Another photo of the back frame.
39) One last photo of the back frame.
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40) The top of the back frame after the cap board had been removed.
The wood residue is veneer that was on the cap board which was still stuck to the
back frame more strongly than it was stuck to the cap.
41) The plate has now been removed, revealing the sound board
better. The board will be given a number of small drilled holes that will serve as
index points for getting the new board and bridges aligned properly.
42) A photo of the back of the plate showing that there is no lip on the
plate to mate with the pin block. You would think that this would make things
easier. It may have been easier at the factory where fast production was primary and
tuning stability and tone secondary. We will be working with this system to
stabilize it as well as humanly possible so that the tone and tuning stability is as good
as the best brands.
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43) This is one of the blocks of wood in which a castor was fitted
in the back frame. You can see from the photo that Foster laid up all the pieces of
the frame by using small bits of left over wood all glued together to save on wood and
keep production costs down. So many extra joints are partly to blame for the failure
of the back frame.
44) The sound board is out and the back frame can be seen along
with the pin block. The pin block is the large blonde rectangle of wood at the top
of the piano. As is common with pianos of this vintage, the outer 3/4" has
three laminations cross grained against each other. Then a thicker single solid (not
laminated) piece backing that up. This is all glued to spacers and the back posts.
If we do remake this frame from new wood, the 3/4" three cross layered bit
will be replaced by a two inch thick 20 layer Delignit panel which will be made in such a
way that all the parts are joined into each other. No butt joints that rely on the
glue to hold them together on the new frame. Also, I will be able to make laminated
gussets (that's the two pieces of wood that you see cutting across the corners) that are
slightly curved to help the sound board vibrate better. The originals are made of
one solid piece of wood which is not fitted into the case by anything but butt joints.
Needless to say, they both came apart when the sound board was removed.
45) The sound board taken free from the piano.
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46) The back frame was not glued well to the sides either.
They came right off the frame as well. That's OK because it means that I can
repair the damage to the sides the bad glue joints caused and glue them to the new frame
with techniques guaranteed never to come apart again.
47) One more shot of the frame. It is only barely holding
together at this point and you can probably see places where it is falling apart. I
checked around with the best rebuilder outside my own shop and they wouldn't even take a
job that had this problem. By following the links below, you can see that I have
repaired such frames more than once in my day. But this is the worst frame I've come
across and am convinced it will be best to spend the $12k it will require to make an
entirely new one of hardwood that is jointed together and made from good wood, not
left-over wood.
Follow these links to see photos of piano frames I've restored using original wood in the past. These photos will reveal the inherent faults of the way that back frames are made. Instead of good quality wood being made up into larger pieces using good joinery and a minimum of pieces. These pianos show how companies use their scrap wood to build up larger pieces that can be slapped together to make the back frame. Since the plates are built very strongly on most pianos, the makers got away with this type of frame construction but I would certainly never want my name attached to the kind of workmanship (or, perhaps, I should say lack of workmanship) that these pianos demonstrate. These pianos did not have the plate challenges of this unit nor the family sentiment that this piano has. It is much more important, in my opinion, to use new wood rather than old for this restoration. For example, one of the pianos that is represented below was finished and shipped sooner than I wanted because the customer lost patience. The other piano is still drying for an additional period to ensure that the soaking off of glue and the moisture issues that caused the problem in the first place have resolved themselves entirely:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
48) This is a photo of the pump before restoration. As with all pianos which have suffered water damage, the bottom of the piano is in the worst condition of all. The pump and other components near the bottom were expected to be in rough condition and I was certainly not let down. This pump was in such rotten shape that most other rebuilders would have thrown up their hands right there and said "forget it." Instead, I will save what I can and replace everything that looks compromised and restore everything that can be nicely restored. I am not afraid of telling a customer that a piano is showing too many signs of damage and that they should forego restoration. I did it just recently, in fact. Got my head bit off! Still, I had to speak the truth whether the owner liked it or not. This piano is a cherished family heirloom, I'm giving them a very good price considering everything she's been through. But, best of all, although there is damage, it is not so bad that the piano cannot be restored safely. It's bad, but it's not lost. In fact, this pump will leave this shop in better condition than it was in when it left the factory as a new pump.
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49) Pratt-Read pumps have the large equalizer/reservoir
pneumatic and the pumping bellows glued to each other without any trunk like one would
find on a Standard or Autopiano. Those piano's pumps are much bigger and are
designed for a totally different type of system. However, they do have one very
sweet little bonus that these pumps don't have. Those high end pumps have a crash
valve. This valve is meant to let air from your pumping action stream by and suck
the reservoir shut while also feeding air to all the other components. Here's the
sweet part, if you give one of the pumping pedals a good solid jab, it will create an air
event inside the system which will suck the crash valve shut and send the high suction
wind you just created with your sudden jab right to the pneumatic stack at the top.
This gives you a nice, quick accent that isn't possible with a Pratt-Read. The air
in the P-R is send from the pumping bellows into the big reservoir and then out from the
reservoir into the rest of the system via a rather fragile, problem prone set of
connections and short air channels. The problem that meets us first is that the
pumping bellows and the reservoir are glued to each other. Since the pump had been
wet and showed signs of water damage I thought I might be able to chisel them apart so
that they could be cleaned up, recovered and put together with gaskets and screws this
time; retaining all the original airways. However, you see in this photo that what I
got for my trouble was a splintered mess. All the stationary boards (all three) were
shattered; leaving only the movable boards still in one piece. And the reservoir's
movable board was coming unglued. More on that later. This photo shows the
remains of the taking apart of the bellows.
50) Another photo of components which came off as I took the pump
apart.
51) So, what did I do? I made new fixed or stationary boards for all
three large pneumatics. In this photo, you can see that I have rehinged the two
pneumatic boards together on one of the pumping bellows. More will be done as I go
along. The criss-cross way the white hinge cloth is put on is used because it keeps
the pneumatic more limber whilst providing a stronger hinge. The design of the pump
demands that the control valves be mounted to the stationary areas of the hinges.
Later, photos will show that I evened out the surface of the hinge with more hinge cloth
so that the finished surface would be flat.
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52) Here are the backs of both pumping pneumatics (bellows.)
The fancy bellows I told you about that had crash capability require the pumping
bellows and the one or more reservoirs to be attached to a common wind line called
a trunk. I am making this up with two trunks. I've added wood strips that are
the same thickness as the bellow's boards. These strips are arranged so as to serve
as thin trunks. They will let the crash valve effect work even through this pump was
never designed to have such. In this photo, the windways have been calculated and
built and then sealed with burnt shellac so that they will be air tight. Since this
design of system has two suction lines from the pump: one from the bass and one from
the treble, I can make two trunks, two crash valves and create a system where the treble
notes respond with accents from a right footed thrust while the bass reacts stronger to a
left footed thrust. It won't be exactly like that or we would need to convert the
entire system over to a type of reproducing player which would require expression valves
and a LOT more money. This will give the player pianist additional abilities to
control the expression of the music. To put it more plainly: this is proving
to be a terrible amount of work but will be a terrible amount of fun later on.
53) Now two pictures of the pumping bellows with their attached
trunks covered with gasket leather. I will punch small holes out of the leather in
strategic areas and drill through the wood. This will allow me to screw the bellows
onto the reservoir so that later rebuilders will not face a no win situation when they go
to restore the pump again decades from now when it is time to be done again.
54) The other bellow.
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55) The reservoir is shown here. The new board I have
made up to replace the one which was shattered is a little thicker than its original which
makes for a better platform for the control valves to rest later on. However, the
movable board has a layer which seemed to be coming loose at the edges. I opened up
the crack to see how far in the bad glue went. This way, I could replace all the
glue that was bad. By the time I was done, I had neatly removed the entire layer.
(FYI: all bellows and reservoir boards are made from plywood in almost all
player pianos.)
56) Gluing the loose layer back onto the movable board of the
reservoir.
57) The reservoir is now complete. Some shaping of both boards had to
be done to make everything fit properly. The hinging was done with the criss-cross
method again and crash valves were made from scratch and placed under each bellows.
The air channels that operate the pedal pneumatic and the wind motor are set into the
reservoir separately from the crash valves that lead to the pneumatic stack. This
way, sudden punches from the player pianist to the pedals will not cause any odd action in
the wind motor and also the wind motor will not be able to lessen the power of the crash
valve nearest to it. Finally, the original design had a very hard felt block placed
inside the bellows at about 1/3 from the left. This caused the bellows to pull shut
and stop on the block so it wouldn't pinch and eventually damage the bellows cloth.
The problem was that the position of this block caused the board to warp badly.
Because it was unglued, I was able to reglue the warped board and make it straight and
true again. Then, I placed that felt block dead center and added two other blocks
with felt so that the board gets even support all the way across. No more warpage.
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58) This is the wind motor governor. Its job is to take
the wind that comes from the reservoir (by the way, the reservoir also acts as an
equalizer - steadying the air from the pumping bellows.) Still, the wind motor is
what moves the roll for you and, therefore, must more with perfect precision. So,
the fairly steady air from the reservoir/equalizer is steadied still further by this
device. It is also within this device that controls dictate how much air will be
permitted to come through the wind motor thus setting the tempo of the music.
59) This shows the cover plate removed and a slide valve beneath
which is attached to a spring loaded pneumatic. This, rather complicated, pneumatic
controls the valve and keeps the speed setting you selected running evenly. An extra
tiny pneumatic is also added to the system just to offset a slight flaw in the governor's
control of the wind. P-R found the governor was off a bit. Rather than
overhauling the entire thing, they added a tiny pneumatic that was pneumatically attached
to the wind nearest the motor and mechanically connected to the control pneumatic
(recovered soon with wine colored rubberized cloth.
60) The device that controls the tempo has had new leather installed and all
necessary restoration completed. It consists of the block that is mounted to the top
in this picture. The tempo is set by a valve that is attached to the wire coming out
of the block. It is usually just set into a felt bushing. In this case, I was
concerned that the job of rebushing the felt was going to cause problems and leakages so I
reinforced its ability to be air tight by installing a disc of leather around it.
This will keep any air loss negligible and still allow the wire to move back and forth
with proper ease.
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