THE
HAMMERS
THE
QUALITY OF THE HAMMER:
This is another
area where you can visibly see quality. Are the
hammers nicely spaced? Are they all in line? Ask the
salesperson about the hammer weight. Good pianos in a
console size use about a ten to twelve pound hammer.
Piano hammers are made of fine wool felt which is
formed around a hard-maple hammer molding.
First-grade piano hammers are made of two layers of
felt; the outer layer is white, the inner usually
purple, green or magenta.
The layers of felt
are applied separately. The forming and gluing of the
felt to the hammer is done with tremendous pressure
applied by hammer presses. Many tons of pressure are
applied from several angles, forming the shape of the
hammers.
The result is one
long piano hammer which is then cut into individual
heads. Holes are bored at the proper angles on the
underside of each head, into which the hammer shanks
are later glued. Each set of hammers is then
individually and painstakingly fitted to the piano.
Some hammers are stapled, others have a cotter
key-like wire through the hammer to insure stability
in the hammer. Many imported pianos have hammer
weights of up top twenty pounds on grand pianos.
One of the least
understood and most controversial subjects in the
world of pianos is hammer weight. The prospective
buyer is told that one piano has twelve-pound
hammers, while another has only nine or ten-pound
hammers. A glance into the piano tells us that surely
those hammers, even all eighty-eight of them, do not
weigh from nine to twelve pounds. The figure refers
to the size of the felt sheets used in the making of
the hammers. The felt in an individual hammer
averages 109/l000ths of an ounce, depending on the
weight of the sheet of felt from which it was made;
and the difference between nine and twelve-pound
hammers average 36/l000ths of an ounce per hammer.
The important thing to remember about hammers like
all other parts of the piano, is that not only the
quality of the materials, but how those materials are
utilized in the building of the instrument determine
the overall quality of the product. In the case of
hammers, the proper shape and hardness are the key
factors affecting proper tone regulation. That's why
it is often said that while a good hammer can't make
a poor piano sound good, a bad hammer can spoil the
best piano.
Like the speaker of
a radio, a piano's sounding board is a vibrating
diaphragm. To work properly, the board must always be
under tension. This is accomplished by having the
center of the board arched, or crowned, with the
strings pressing down on the board where they cross
the bridges. The vibrations of the strings are thus
transmitted through the bridges to the sounding
board, where they are greatly amplified by the board
and projected into the air to reach our ears.
The piano string
acts as a tone generator. The sounding board's
function is to truly reflect and amplify that tone.
The sounding board is the most important single part
in the piano because if the board is bad, you do not
have a piano until there has been a major repair job.
No real music can come out of a conventional piano
except through the sounding board. So that it will
vibrate freely, a sounding board is necessarily a
very thin panel, usually from 3/16 to 3/8 of an inch
thick. Ribs are added to stiffen the board and to
help preserve the crown. The reason the ribs are
shaped at the ends is to allow the board more
flexibility around its perimeter. Until recent years,
all piano sounding boards were made of solid lumber
pieces glued edge to edge. Wood, however, has an
irresistible tendency to absorb or lose moisture
according to the humidity content of the surrounding
air. Absorption of moisture causes the conventional
sounding boards to expand, increasing the tension of
the strings and, thus, raising the pitch. Conversely,
the pitch is lowered when the board dries out. It has
been a constant struggle to try to keep such sounding
boards from splitting or from losing their
all-important crown. To obtain perfect musical
results, there must be good contact between each of
the strings and the board. This perfect contact
cannot be maintained if the board loses all, or even
part, of its convex form (crown). Piano sounding
boards are made of wood because no other known
material amplifies musical tones so well.
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