Restoration of a Mason & Hamlin Ampico for David Lucas Graves & John Herrmann
241) 
242) 
243) 
241) Now that the sound board has been marked, a knife is
used to score the pencil line. This prevents the saw from splitting out wood fibers
into the area of the sound board as it is cut out.
242) The rough cut board is then placed into the piano, marked and sanded until it
fits the rim as perfectly as possible. Tiny discrepancies are OK provided they are
so slight that the squeeze out of the glue will be more than adequate to fill them.
It isn't necessary to get the board fitted so tightly that you can't fit a piece of paper
between the board and the rim anywhere along its length. However, the fit should be
tight enough that this is very nearly the case.
243) Fitting the pre-crowned ribs to the piano.
244) 
245) 
246) 
244) Aligning the old board to the new one using my index
marks and transferring landmarks.
245) Now the new board is marked along its edge for the diaphramizing process.
This thinning process makes the sound board more flexible along its edges.
The first step in this thinning process is to mark the edge of the board appropriately as
a guide. Then a fine toothed saw is used to make angled cuts into the board.
They go down to the mark on the edges and taper off to nothing at about six inches.
The goal is to line the thinning up with the places where the ribs thin out as well.
All edges of the board are thinned except those near the upper section of the
treble bridge. This area requires the board to be thicker for better tone
production.
246) The first step is to use a block plane to remove the bulk of the wood down to
the marks. Then a smoothing plane is used to clean up the marks left behind by the
block plane. Finally, a sander is used to do the final cleaning up and smoothing.
247) 
248) 
249) 
247) The board is now ready to be indexed to its ribs and
glued up in the sound board press.
248) Before doing the work of mating the board into the case and to its bridges, I
glued the pin block into place. The way the pin block fit is designed on this piano
makes for a really nice finished product. The pin block actually had to be driven
into place in the bass in order to fit into the slot provided for it. Care was, of
course taken no to damage anything during this. The plate heights were matched
(treble and bass) to the original plate height and then the plate and pin block were
screwed together and then glued into the case. In this way, the block will mate
perfectly with the plate and the case of the piano all at the same time.
249) A shot of the pin block after it was glued into place. Next, it will have
to reinforced with dowels before it will be finished.
250) 
251) 
252) 
250) Setting up the sound board press for making the new
board. Using the old board makes it possible to get all the clamping cauls oriented
correctly before putting the new board into place.
251) Gluing the ribs to the sound board.
252) The ribs are now glued into place. I use a water resistant (boat grade)
epoxy to glue the ribs. The epoxy has excellent acoustic properties and contains no
water. By using it, I don't introduce any water to the spruce during the gluing
process. That helps keep the board from changing shape from the moisture contact
while continuing to provide an excellent glue joint.
253) 
254) 
255) 
253) Using a plane and sander, I shape the profiles of the
ribs to match the original design.
254) Now the board has been put back into the piano and all ribs checked to make
sure the seat completely into their mortises. Next, a mark is made around the board
to show where the gluing shelf (called the rastin) is located. The gluing surface
is, then, taped off and then the board is coated with a layer of the same epoxy. I
use a thin layer. It serves to harden the outer surface of the board without
penetrating the wood very much. Lacquer and varnish penetrate the wood more which
weighs the board down because extra coats are required. The epoxy provides an
excellent water barrier, a hard surface which pushes the air well during play and is very
light so as not to slow down the action of the board. The tape keeps me from getting
epoxy onto any areas that will later be glued.
255) Now the board is placed in the piano, the bridges laid in place and the plate
set over them. With the plate in its correct location, I can use measuring tools and
strings to adjust the locations of the bridges for a perfect location. This is more
accurate than attempting to copy the bridge locations from the old board (which is what I
used to do).
256) 
257) 
258) 
256) Gluing the bridges to the board. The design of
the press allows me to impart the correct crown into the long bridge to sound board joint
just as I did with the ribs. The long bridge is, in fact, the most important rib on
the sound board.
257) The board after the ribs were glued into place. It will now have to go
back into the hot box for a couple days before I proceed with anything further on it.
258) The glue surface where the board will attach to the rim of the piano is marked
and then taped off. Then the board is sealed with a special epoxy which seals the
wood, adds hardness to the surface and prepares the wood for lacquer. This photo
shows the back of the board after the epoxy had cured and the lacquer work was done.
You can also see the work which was done to reinforce the joints between the
bridges and the sound board. Mason & Hamlin pianos use a combination of screws,
dowels through the ribs and larger, special dowels backed up with hard maple blocks.
The bridges on a Mason & Hamlin is traditionally more well secured to the sound
board than any other make of piano.
259) 
260) 
261) 
259) Another angle of the same thing shown in the previous
photo. I like to seal my boards with a very thin layer of epoxy. The epoxy,
unlike varnish, shellac or lacquer does not penetrate the wood very deeply. This
keeps the finish more on the surface and less penetrative into the spruce. This
actually leaves the board more flexible and light than using straight finish. Also,
the epoxy cures to a much harder surface than lacquer which means that the finished
surface will be much better at pushing air than if it was simply finished with lacquer,
shellac or varnish.
260) Now the rim of the piano has to be prepared to receive the board. Most of
this work was done long before but some contamination builds up over time and so the glue
surface needs to be freshly cleaned before gluing. Next, cauls must be custom made
to fit the piano perfectly. These cauls cannot be transferred from one piano to the
next since each piano we work on is slightly different from all the others. Finally,
the pressing cauls which transfer the clamp pressure to the bottom cauls must be set up.
I have a large set of these cauls which you see at the bottom of the photo.
These are chamfered at their bases to 1 1/2 degrees to correspond to the chamfer in the
rastin (the gluing ledge in the rim of the piano.) Also, these cauls have various
angles cut from their edges to ensure that they can be lined up along the rim very
tightly.
261) All the gluing up is done. The glue is applied liberally to the rim and
the board placed onto the rastin. Then the clamping cauls are laid around the
perimeter of the board and the transfer cauls are placed over those. Then the clamps
are placed and tightened several times until they are at their maximum tightness. I
use these particular type of clamps because they are very good at setting the clamping
pressure perfectly. Bar clamps can put out too much pressure and some other types of
ratchet clamps as pictured here don't put out enough.
262) 
263) 
264) 
262) Another shot of the finished clamped up sound board
assembly. I will let this sit for at least a week until the glue is totally cured
before removing the clamps.
263) This is a photo of the action rails with the original guide hammers and the
originally felted hammer lift rail still in place. Like so many of these hammer lift
rails, the rail itself has a resonant "note" to which it rings or responds.
I have always tried to replace these rails with shifting actions on all pianos that
were not players but this rail is needed by the Ampico and must, therefore, be retained.
It falls to me to endeavor to silence this rail so that it will not interfere with
the music being made by the piano.
264) Step #1 in silencing the rail was to clean off the old worn out and hardened
felt. I then drilled holes into the wood (but not into the metal "U"
channel that surrounds that wood and set lead weights into the wood. These might be
construed as adding unneeded weight to the rail but the mechanism that operates this rail
is given full pump pressure and is more than up to the task of lifting the weight and many
times more. The lead slugs should help to block the inherent vibrations in the rail
for us.
265) 
266) 
267) 
265) After the rail was deadened with lead slugs, it was
covered with soft thick felt which was overlaid with a layer of even softer felt.
The other tasks to be done with this are to rebush the pivots on which the rail runs and
to put new leather onto the arm which actuates the rail from within. The design of
the leather on the actuation arm was to use heave "shoe-type" leather which was
screwed to the arm. The screws could hold the leather because of its rigid and tough
structure. You can see the old leather piece and the new replacement piece in the
bottom right corner of the photo.
266) This photo shows the pivot arms which have been polished, clear coated to
prevent corrosion and rebushed.
267) This is another photo of the rail with the new leathers and all the other
aspects just described.
268) 
269) 
270) 
268) The hammer lift rail has platforms it comes to rest
upon when the rail is at rest or released from its raised position. The original
felt used for this was hard hammer felt which made a considerable noise when the rail
returned. In an attempt to quiet the rail, I have replaced the old felt in this
photo with new softer felt.
269) This photo shows the new leather which is screwed to the lifting arm attached
and complete.
270) This photo shows that the shank and flange rail (which was originally covered
with sand paper to help keep the parts from creeping out of position) has had new course
sand paper glued to it after the old paper was thoroughly removed and the wood cleaned and
leveled.
271) 
272) 
273) 
271) This photo shows the let off rail which is used to
adjust the instant that the whippen jacks are to release their control over the hammer and
let it fly up to the string. This action is called escapement and is one of the keys
to how the modern piano action works so well.
272) This photo shows the guide hammers back in place, the sand paper pierced to
permit each flange screw to enter and also shows a difference in the hammer rail.
After all was put back together, I found through researching the function of the rail that
my felting scheme did not silence the rail enough. I, therefore, took the time
needed to remove the first felting attempt and replaced it with a different one. In
this configuration, a strip of red felt was glued to the rail and then a thick strip of
felted wool cloth was glued over it. The wool cloth was only glued down along one
edge and the rest of it was permitted to continue to remain free. This should not
only help to eliminate the felt's tendency to pack down over time but also helped give me
that silencing I was looking for.
273) Sorry that this photo is a little fuzzy. The soft felt pieces I placed on
the rest blocks was not quiet enough and it did not satisfy me dimensionally either.
I opted for a more complex and difficult to make solution that truly quieted the
rail return, gave me the silencing I was looking for and enhanced the felt's ability to
remain as it is without packing down over time. The layer of softer felt was covered
with a firmer layer of felt. This red covering strip of felt was stretched with
considerable difficulty over the under-felt. This created a double felt and a
spring=like action. The layers of felt are not glued together. The red
stretched felt is glued down at its ends. This extra work on the rail helped to
quiet it considerably.
274) 
275) 
276) 
274) The main rim of the piano has its key bed taped off and
has received its lacquer. It only remains to let the lacquer dry and cure completely
and then it can be rubbed out.
275) The two cover boards for the drawer after they were sanded out and buffed to
the appropriate gloss. The boards are now receiving a coat of quality wax.
This wax will do two things for us. It increases the gloss and also makes the piece
more slippery. This slippery nature helps to prevent scratches caused by dust
particles that land on the wood. This is especially useful during transport and also
during dusting. I use a paste was now when I used to use Gaurdman's Polish.
The Guardsman's was an excellent product but, once it had cured, it was so tough that it
was impossible to remove if the customer wished to change out the polish later.
This wax hardens to a nice surface but additional layers of the same was will remove older
layers and you can remove all of it with simple paint thinner; a thinner which is
nonreactive to the lacquer.
276) The lid support prop is finished and a leather piece is being installed where
the old one was. The original was done with a small circle of felt covered with a
second circle of felt. While this solution answered the need, the leather adds a
nice touch of elegance. The leather dot under the visible circle of leather adds
shape to the cushion and improves its longevity.
277) 
278) 
279) 
277) The pedal mechanism before work on the inner mechanisms
began. The Mason and Hamlin pedal mechanism is, by far, my favorite pedal mechanism
of all the makes. That includes Steinway.
278) The pedals have been cleaned and polished. A strip of lubricated leather
is attached to the pedal itself because a spring rides long the pedal right there and
needs something to quiet its action. I increased the roughness of the brass where
the leather will be glued into place so as to enhance the holding power of the glue.
The red circles were cut out by me to match the original white ones. These
form a cushion between the pedals and the wood guide blocks on which they pivot.
279) The pedal lyre has been complete in terms of cosmetics and structure and now it
is time to rebush all the necessary points and reinstall the hardware. This photo
shows the re-polished pedals secured in place. The design of these Mason and Hamlin
pedals is such that the pedals themselves pivot on a bare wooden hole in the sides of the
support blocks. When these holes get worn and sloppy, they have to be drilled out
and bushed. However, at this time, the holes are in acceptable condition so I only
had to concentrate on rebushing all the other areas of the mechanism. In this
photo, some of those new bushings can be seen and the under side of the polished pedals.
© Copyright 2010 {David Rodgers' Piano Rebuilding}. All Rights Reserved.