[ Ref. The "Cement" Lauter Piano, 040411 MMDigest ]


>> Can it be true?  Cement/concrete piano cases?  And even with a veneer
>> look?
>>
>> If it were possible, it had to be reinforced cement or concrete.  In
>> order to produce the needed parts you would need rather complex moulds,
>> which would be very expensive.  Apart from the question if it was, from
>> a technical point of view, [it was] already possible to produce such
>> parts those days.


The construction technique would likely have been 'ferro-cement,'
which typically doesn't require molds and has been used for various
applications since perhaps 1900.  You start with several sheets of
heavy wire mesh, perhaps of 1 mm wire woven into 1 cm squares.  These
are layered together into one heavy sheet.  You then build your piano
case out of these sheets, thus creating a piano case out of wire mesh.

A light steel framework would probably have been added to better define
the shape of the case.  I would guess that threaded studs were welded
to this frame so that legs and sounding board and plate could be
attached later.

You then mix a fairly stiff mixture of Portland cement and sand.  Use
a trowel to smear the concrete mix over the wire such that the concrete
thoroughly penetrates through to the opposite side.  A companion waits
on the other side of the mesh with a trowel to form and smooth the
concrete that is pushed through the mesh.

The resulting structure is very stiff and strong.  It is sufficiently
light in weight that a boat can be built of it.  I read about a
ferro-cement ship that was in regular service for many years, but
I have no reference.

However, there are a great many references to canoes made in this
manner.  Civil engineering schools traditionally participate in an
annual "concrete canoe" competition in the USA.  My own school, the
University of New Haven, has traditionally done quite well in this
contest.  But since one canoe is built per year, there is a disposal
problem: the vessels are very difficult to break up and will not
decay or otherwise disintegrate.  Many engineering schools thus have
a flotilla of these things somewhere on the premises.  The University
of New Haven gardeners solved our particular problem by using them for
flower planters, for which they are admirably suited.


>> How would you mount these concrete parts?  Surely not by using the
>> commonly used screws for wood.


I would think that the piano case would have been equipped with the
threaded studs mentioned earlier.  The veneer could be glued on later
with a suitable adhesive.  This last task might have been the biggest
obstacle; it's difficult to glue things to new concrete.

I once came upon a pair of high-quality loudspeakers made of
walnut-veneered concrete.  This was at a high-end audio store, so the
price was likely outrageous.  The steel mounts for the speaker drivers
were cast into the concrete.  The units were memorably heavy.


>> And if concrete piano cases really did exist, how come we do not find
>> any information about this in the archives?  Not even in the hugest
>> archive of all: the Internet.


Indeed, the entire enterprise might be mythical, or partially so.  But
the process is certainly plausible.  As for the Internet, I suspect
that my experience matches that of many people here: I have searched
for many topics that are either non-existent or hidden from search
engines.  And, of course, a search for "concrete piano" will now yield
this present bit of lore in MMDigest.


>> In order to make the investments profitable many concrete cases would
>> have to be sold.  But Lauter was, like most builders, a rather small
>> company, and did not build so many instruments.


Ferro-cement is much like hand-laid fiberglass: you can make your
articles one at a time with minimal -- or nonexistent -- tooling.  It
is a method that is famously well-suited for short runs.  Sculptors use
it, as do architects.


>> One important aspect also would be that a concrete case would not improve
>> the sound of the instrument, to say it carefully.  After all, the case
>> has quite a lot of influence on the sound of a piano.  Concrete, being
>> massive, would either absorb the sound.


But it _is_ soundproof, and that may be its benefit.  My uniformed
impression of piano acoustics is that only the sounding board should
vibrate, not the piano case.  Thus a sheet-steel piano likely would not
have a desirable sound.  (There were, of course, the famous aluminum
pianos used aboard the Zeppelin dirigibles.)  But a concrete piano case
might well have acoustic properties similar to that of thick laminated
maple.


>> Permit me to tell you a story.  Over here, in Holland, a furniture
>> factory was only using massive oak.  This was their main sales
>> argument.  Their products were also quite huge, thus heavy.  Somehow
>> (about 1975) rumours were that this heaviness was caused by concrete,
>> which was hidden inside the wooden parts.  Despite the fact that the
>> factory argued that making such products only would make them by far
>> more expensive, and also would result in a lower quality, and despite
>> the fact that they invited the press several times to visit their
>> factory, the public did want to believe the story, and the factory
>> had to close its own shops, followed by the closing of the factory.
>>
>> Might be the concrete piano is a look-alike story?


Possibly.  I once repaired an inexpensive European-made clock radio
whose apparent quality had been enhanced by a heavy (~1.5 cm) steel
plate screwed to the bottom of the case.


>> However, sometimes a piano can be a lot heavier as normal.  If an
>> instrument was to be shipped into tropical regions, some companies were
>> building reinforced models.  The main reinforcement was provided by
>> glued connections with quite many additional screws.  If the glue
>> would loosen due to the tropical climate, the screws still would hold
>> things together.  Have you ever seen a sounding board which was almost
>> totally held together by screws?  I did.  The piano was re-emigrated from
>> Indonesia.  And believe me or not: it still did sound (and rattle,
>> also).


There are similar stories about the wooden glider aircraft used during
World War II.  It took a great deal of experimentation to get the glue
to adhere properly in damp environments.  You can read about this in
a splendid book called "The New Science of Strong Materials", by J. E.
Gordon.  I think this should be required reading by anyone who works
with a variety of materials and adhesives.


>> Apart from the additional screws (and impregnating the felt parts of
>> the mechanism), they might use massive hardwood for the case instead
>> of veneered softwood, to attain a better resistance against all kinds
>> of wood-loving worms, and so on, which are very common in that climate.
>> This also did make the piano heavier.  Needless to say that such
>> instruments were very expensive.
>>
>> I did find some information about the Lauter company.  They indeed seem
>> to have sold into tropical regions, so maybe the so-called "Cement"
>> Lauter is just such an instrument meant to be used in those regions,
>> thus being quite heavy due to the method of its construction.


I understand that pianos used in tropical environments can have
distinct problems.  I read a story, purported to be true, about a piano
recital in the Philippines or Indonesia or thereabouts.  The pianist
started off okay but then a key stuck, presumably due to the humidity.
He was somehow able to compensate, and continued until a few more notes
stuck.  He struck at the keys to free them to no avail.  Finally, in a
fit of blind rage, he seized a fire axe from offstage and proceeded to
chop the instrument to pieces.

I have no idea if the concrete piano truly existed.  However, such an
instrument _could_ have been built, and it might well have been a good
idea.  The structure would have been cheaper and more stable than wood,
it would have had some desirable acoustic qualities, and it could be
constructed by workers of lesser skill than traditional piano cases.
But the purchasers of pianos are very conservative, so the enterprise
would probably not have been a financial success.  My guess is that if
the instruments did indeed exist, they were something of an experiment.

I suppose it's clear that I sort of like the idea of a piano made with
non-traditional materials.

Mark Kinsler

 [ Long ago (1950s?) I read an article about the physical and acoustic
 [ properties of an exponential horn concrete loudspeaker.  The author
 [ noted that, compared to wood contruction, the concrete was almost
 [ absolutely stiff and without acoustic energy loss due to flexing.
 [ It seems the same should be true for the body of a concrete piano
 [ or guitar(!).  -- Robbie