PIANO TECH

On the Care of a Period Piano

Kenneth Drake

 

The comments below are based on personal experience with these particular pianos and may not be applicable to the reader’s instrument.

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John Lyon, fortepiano

As a modern copy of Anton Walter there are no damper or moderator problems. Individual taste will necessitate experimentation with types of leather, the size and shape of the hammer core, the tightness of the striking point leather stretched over this core, the relative smoothness of the striking point, and the evenness with which it meets the two or three strings. The learning process is ongoing.

The hammer cores from b-flat ¹ upward in the treble have a tapered core of two to three layers of thin pigskin, in some cases each hardened with lacquer (fingernail polish). The most satisfying striking layer leather, chosen to produce a subjectively desired sound, is sheepskin donated by a local fur and skin business.

The area of the treble where the balance between life and hardness, between brilliance and warmth, seems most difficult to attain is the octave between c² and c³. The tightness of the top leather over the core – whether more or less – has an immediate effect on the sound. For a brighter sound, one way is to “iron” the striking point leather with a heated kitchen spatula (of the type one would use to frost a cake…), but this must be done in gradual steps, not aggressively, in order to avoid going to far and getting an unpleasant tone. A better way may be to depress the string marks on the hammer with a hot needle – better because the remainder of the leather is not compressed but retains a cushion quality. Better still would be to listen to each string and use the heated needle only on the mark that produces a less bright sound.

While a professional restorer might use hide glue (the top leather is of course glued only on the ends) Elmer’s Glue-All can be softened with heat. Considering countless trials loosening and tightening the leather, ease of softening the glue with a heated pocketknife is virtually a necessity.

A buzzing sound with the impact of the hammer on the string is the result of the hammer striking the strings unevenly. Raise the dampers, hold the hammer against the strings with a hook made of a coat hanger, and pluck the strings for sameness of pitch. The border on a book of postage stamps is useful for shim material; being self-adhesive it stays at the precise point one has placed it when re-gluing the leather.

A clicking sound when the hammer strikes the strings, barring a loose hammer, is caused by the arms of the capsule in which the hammer rocks being too loose. Remove the hammer, squeeze the arms of the capsule together for a tighter fit, and replace the hammer.

A hammer that does not repeat reliably is usually due to being caught too low on the backcheck.

 

Broadwood grand, 1806

Out of respect for the expertise of the original builder, it seems wise not to do repair or alteration that cannot be reversed. Except for five re-covered hammers on this piano the leathers are original, the tone ranging from acceptable to ravishing. A few hammers have become harsh-sounding and can be improved by rubbing the striking point with another piece of leather. If this is not effective, the best advice may be, “Live with it…” Stretching the top leather by inserting a toothpick underneath the layer, as one might do with hammers in the fortepiano, is likely to result in dullness.

In this piano also, a note that does not repeat well may be due to the hammer being caught too low on the backcheck.

Because of the twist in the case the pitch is best left at least a quarter-step low. The piano has also been re-strung approximately two gauges lighter. One surmises that, in its pristine state strung with original gauge wire, the piano must have sounded like the Steinway of its day.

 

Broadwood grand, 1816

The tuning pins in the 1806 grand have been replaced with modern pins at some point in the past. The pins in the 1816 piano are original square pins without an opening for inserting the end of the wire. The coil has to be turned on a smaller size brass pin (in which of course a hole has been drilled) and then worked on to the larger tuning pin. It is probably unnecessary to mention that a pin should not be driven into the block unless a jack or similar firm support has been inserted between the pinblock and the action floor. A loose pin can be seated more firmly by inserting a sliver of emery cloth in the hole before driving the pin into the block.

The slight loose play of the hammer at its point of rest is not a defect of regulation, instead giving the jack room to slide back under the notch in the hammer shank butt. Eliminate this apparent lost movement and the hammer will not be “cocked” for the next thrust against the string.

Humidity level of the room during the heating season from any of these pianos is best kept at 45% to 50% in order to avoid sticking dampers, loose hammers, and more serious damage.

The 1816 grand is sufficiently “modern” that similar observations for minor maintenance may be applied to the later Broadwood grands.

The basic lesson from use of such instruments of the past is not just “playing a concert,” but personal responsibility for tuning, regulation (admittedly of a simple action), and remedy of problems of tone and control. Everything relates to the maxim, Ars longa, vita brevis.