In pianos where the treble notes are not of good quality, or where the strings are continually breaking, considerable improvement will be effected by renewing the top octave, the increased brilliancy obtained by this means well repaying the trouble taken.
To repair a broken sticker hinge, unscrew the button from the damper wire. The sticker can then be separated from the lever to which it is glued, and removed from the action. The old hinge is then picked from the slot and from the hammer butt. For the new hinge cut a piece of fawn leather rather larger than the finished size. Hammer it to a sharp bend at the middle, which just touch with thin glue and press into the slot with a blunt table-knife. The hinge is then trimmed to its proper size, and the damper wire passed through its socket In glueing to its place, avoid being toe liberal with the glue.
To re-hinge lever, damper, or hopper: One portion of either of the two first will be found adhering to its rail. This must be detached with sufficient care to avoid tearing the wood; a hot iron then applied to the part immediately above the broken hinge will destroy the old glue, and permit the groove to be sprung open (not entirely separated), so that the parchment may be removed, and a new piece inserted. The joints are then pressed close with a small screw or tied round with thread until the glue is set, any superfluous glue being previously removed from the hinge.
Centres sticking nearly always arises from damp, but with the exception of the keys, is happily not of common occurrence. When it happens with the hammer centres, the only permanent cure, other than removal to drier premises, consists in taking the entire action to pieces, and broaching the centre cloths; but this is so difficult of execution that few, even practical hands, would care to undertake it. When a heavier touch is not objected to, a remedy has often been found in glueing small pieces of weighted pine at the back of the stickers, sets of which are sold expressly for this purpose.
Keys sticking are remedied by slightly easing the front hole with a small flat file, care being taken to remove only sufficient wood to take away the pin mark. To test if the key also binds in the centre, lay the key so that the centre pin just enters the countersink of the round hole, when its own weight should be sufficient to cause it to sink to its proper position. If it does not do so, the centre square hole also requires easing; the round hole rarely needs altering. Keys will also occasionally stay down where, in consequence of the frame warping, the front pin is out of the hole. This can be detected by the mark; where, on the contrary, through hard service, the keys have become loose, and rattle, a new and larger set of pins may be substituted. This will be found quite as easy to do, and a much more effectual remedy than wedging the holes.
Blocking is caused by the hoppers not "setting off." The effect of this is most unpleasant, as the hammers then block or jam against the strings, and deaden all vibration. The regulating wire in the hopper should be un-screwed about half a turn, so that the hopper slips from under the lever just as the hammer reaches the strings. Where the blocking is accompanied with a creaking noise on the keys being pressed down, it is the effect of damp, and on examination it will be seen that the top of each hopper has become rough through the softening and consequent abrasion of the blacklead (graphite). A little of this applied damp with a small leather pad, and afterwards burnished with a piece of smooth steel (such as the barrel of a tuning hammer), will put matters right. Where the blocking occurs from the check of the hopper, the touch is too deep for the blow, and a piece of brown paper should be put under the baize at the front of the keys.
Of all the ills to which a piano is liable, the effects of moths and moisture are the most disastrous. Of the two, the former is perhaps the more destructive, because the attacks are more insidious, and the mischief is generally very far advanced before it is discovered. There is no part of the action, however small may be the aperture, that will escape the ravages of the grub, and many a fine instrument has in a short time been converted by them into a complete wreck, and even after a thorough repair and supposed complete extermination of these pests, the destruction will often recommence; so that wherever there seems reason to suspect their existence, the most rigorous examination and cleaning of all parts of the interior is imperative. A saturation also of the suspected parts with spirit and camphor has often been found productive of good effect.
To guard against damp, it is advisable that a piano should never be placed, if it can be avoided, on a stone floor or close against an outside wall. Where this is impossible, it is better to raise it either on a thin wooden partition or on "insulating " glasses, so as to allow a passage of air all round; also occasionally removing the front, and where the hammers seem inclined to stick, place the action at a little distance from the kitchen fire. Other symptoms of damp and the way to cure them, will be noticed farther on. Durability. - Pianos that have been made within the past 20 years or so are, both in frame and mechanism, of much greater durability than those of earlier date. In the latter, among other shortcomings, the action centres were so tender, even when comparatively new, as to require the greatest care in handling; whereas, in the more modern instrument to effect a casualty would take an amount of force not likely to be exercised, so that with common care the different parts may be taken asunder without the slightest risk. As a rule, the public are slow to appreciate this, and the old fear of meddling with any portion of the interior still exists.