Piano Tuning Part 5

1. _Key_.--Keys stick; that is, after being struck, they fail to come up quickly, if at all. First ascertain if the trouble is really in the key, or in the upper part of the action. To do this, lift the extension or wippen until the upper part of the action is entirely free from the key, so that you may test the key independently. Some keys are leaded so that they will fall in front of the balance rail, others so that they will fall back of it; in either case, lift the low end and let go, to see if it will fall by its own weight. If it seems quite free, you may know the trouble is not in the key; you will also find that when you release the extension or wippen, it will not fall readily, showing that the trouble lies in the upper part.

If the trouble is found in the key, examine the guide pin. See if it is placed in a direct line with the key. If so, and it still binds, enlarge the hole by pressing the wood back slightly with some wedge-shaped instrument, if you have not a pair of the key pliers which are used for this purpose. See that the cloth, with which the hole is bushed, is not loose and wrinkled. Do not oil or grease the guide pin unless such treatment has been previously resorted to, as the polished pin will work more freely in the dry cloth. Do not pinch hard on the pin with rough pliers and spoil the polished surface.

Sometimes you will find one key warped so that it rubs on the next, in which case, plane off a slight shaving to free it. Sometimes changing the position of the guide pin will straighten or level the key and make it work all right.

The balance pin is subject to some of the same difficulties as the guide pin. See that it sets properly and is not bound by the mortise.

Sometimes a splinter will be found on one side of a key where the lead has been put in. A piece of any foreign material between two keys generally causes both to stick.

Where the action is too deep, that is, the keys go down farther than they ought, place cardboard washers under the felt ones around the guide pin, or raise the felt strip under back end of keys.

Where the action is too shallow, place thin washers under those around the balance pin. When this is done, the whole action must be regulated accordingly, as this alteration will make a change in the working of the upper part of the action.

2. _The Bottom or Capstan_.--This should be so adjusted that when the key falls back to its rest position, the point of the jack will just spring into its place in the nose of the hammer b.u.t.t. If held too high, the jack fails to catch in the nose, and the key may be struck without producing any effect on the hammer. When the bottom or capstan is too low, the point of the jack will be some distance below the notch, which will cause what is known as lost motion, it being necessary to depress the key a portion of its depth before the jack can act upon the hammer. Depress the key slowly, watching the hammer, and the fault will be discovered.

After a piano has been used for some time, the keys that are struck most frequently (those in the middle of the instrument) will be found to have this fault. The felts under the keys and those which are between the working parts of the action become compressed or worn so that the jack will be found to set so low that there will be lost motion in the key. In this case, loosen one of the screws in the bottom and turn the other down so as to move the jack upward until nearly all lost motion is taken up. A little play is generally necessary, but very little. In case the action has a capstan, simply turn it upward.

3. _Back Check_.--Blocking is most usually caused by the back check being too near the back catch, so that when the key is struck, the back check holds the hammer against the string. This should be seen after raising the bottom or capstan as above referred to. It will be observed that when this is done on account of the wear of the felts, the back check will stand much nearer the back catch than it did before, and will need bending back so as to give the hammer plenty of "rebound." A steel instrument with properly shaped notches at the point, called a regulator, is used for bending wires in regulating the action. See that the wires stand as nearly in line as is possible. In old actions that are considerably worn, however, you will be obliged to alter some more than others.

4. _Bridle and Bridle Wire_.--In putting in a new bridle, it should be doubled over at the end and secured to the hammer b.u.t.t by a small tack. Be sure you get it exactly the same length as the others; otherwise it will be necessary to bend the bridle wire out of line.

Some tuners glue the bridle around the back catch stem, but the above method is preferable.

The purpose of the bridle is to jerk the hammer back quickly and the wire must be set, neither so far back as to check the stroke of the hammer, nor so far forward that the bridle is too slack to draw upon the hammer.

5. _Jack_.--The jack itself seldom gets out of order. So long as its f.l.a.n.g.e does not come unglued in the wippen, or its spring get out of place or broken, or get tight in its joint, it will need nothing. Its adjustment and action is controlled by the bottom or capstan, and the regulating b.u.t.ton.

6. _Regulating b.u.t.ton_.--This b.u.t.ton determines the point in the stroke of the hammer where the jack flies off from the nose of the b.u.t.t. If the b.u.t.ton is too high, the jack does not fly off soon enough, and the result is, that the hammer either blocks against the string or bounces from the jack after the stroke has been made, striking the string a second or third time from one stroke of the key.

The felt punching on the lower side of the b.u.t.ton often wears until this trouble prevails. Lower the b.u.t.ton by turning down the screw on top of the regulator rail; if lowered too far, however, the action is weakened by causing the jack to fly off too soon, without giving the hammer a sufficient impulse. A regulating screwdriver is used for this, but in its absence, a wire hook, similar to a shoe b.u.t.toner, will turn the screw.

The block rail is properly adjusted at the factory and requires no attention.

7. _Hammer b.u.t.t_.--The felts and leather on the heel of the hammer b.u.t.t wear out and must be replaced. The felt cus.h.i.+on, that is lowest and farthest to the left (see ill.u.s.tration), is the one that wears out first. The jack, in returning to the notch, strikes this cus.h.i.+on, and in time wears it away so that the jack in returning strikes the wood of the hammer b.u.t.t, producing a sharp click, which is very annoying, to say the least. This click is heard at the instant the key rises to its rest position. Sometimes, however, a similar click is produced by the top of the key striking the board which is set over the keys, due to the cloth being eaten off by moths, or a pencil or some other article lying on the keys back of this board.

The center pin in the b.u.t.t of some cheap actions is not held in the b.u.t.t by metal clip and screw, and if it gets loose so that it works out, must be replaced by a larger pin. The size of center pins generally used in the factory, is .050 of an inch in diameter; the size for repairing should be .053. All of the best actions have the set screw with which to make the pin fast in the b.u.t.t.

Hammers stick when the center pin is too tight in the f.l.a.n.g.e. The bus.h.i.+ng in the f.l.a.n.g.e often expands. Some tuners oil at the ends of the pin with kerosene or wet it with alcohol, which is very good; but a better plan is to shrink the bus.h.i.+ng with a drop of water on each side so that it will penetrate the bus.h.i.+ng. After this is done, the piano cannot be used for a day or two, as the water first swells the bus.h.i.+ng, making all the hammers stick; but when they are dry again, they will be found free. This may seem a curious method, but you need not be afraid of it; it is the most effective.

Before leaving the hammer b.u.t.t, see that the hammer spring is in its place.

8. _Hammer Stem_.--These sometimes warp, split, crack, or come unglued at the b.u.t.t or hammer. If twisted so far that it does not strike properly on the strings, or that it binds against the next hammer, the best thing is to put in a new stem. If merely split or unglued, it may be repaired. Sometimes a click is heard and it will seem impossible to find the cause, the hammer and stem apparently perfect, but a close examination will reveal a looseness in the stem somewhere.

In putting in a new shank, drill or chip out the old one, sc.r.a.pe the holes out clean, take your measure carefully, and do not make the new shank too tight, but large enough to fill the hole snugly. Apply glue to the ends of the shank and also in the holes. Cedar is used in some makes, but good maple is stronger, and is more generally used.

9. _Hammers_.--When too hard, soften with a felt pick. Do not raise the felt up, but stick the pick in the felt just back of the point and this will loosen it up and make it softer and more elastic. Where the strings have worn deep grooves, sandpaper them down nearly even and soften the felt as above.

In regluing the felt to the head, glue only the back ends of the felt, and clamp with strong rubber band till the glue sets. Use tailor's chalk (fuller's earth) to clean hammer felts. To harden or draw felts back in shape, place a damp cloth over them, and then pa.s.s a hot iron over it.

10. _Dampers_.--Damper felt often gets hardened so that when it comes against the vibrating string, it causes a sort of buzzing sound.

Loosen it up with the pick. Imperfect damping can sometimes be corrected in the same way.

The damper head sometimes turns round on its wire, leaving one or two strings undamped. Tighten the set screw. See that the dampers are in line; and that they will stop the tone properly when the key is released.

Damper springs sometimes break. It is necessary to take out the damper lever to put in a new one.

See that the spoons are in line and work properly. Press the sustaining pedal down, and see if all the dampers are in line; if not, bend the damper wires with the regulator until they line up perfectly.

11. _Damper Rod_.--When the sustaining pedal squeaks, look first to the pedal, then to the wooden rods leading up to the damper rod. If the trouble is found in any of these, or the springs, use sperm oil or vaseline.

Catch hold of the damper rod at the left behind the action and work it. If it squeaks, you will have to take out the action and oil the swings where they are hinged to the main rail.

QUESTIONS ON LESSON V.

1. If you should find a key sticking, how would you determine the cause?

2. Name all the defects to which the key is subject.

3. Describe the proper adjustment of bottom or capstan.

4. Give two causes of blocking.

5. Give the purpose of the regulating b.u.t.ton, and its proper adjustment.

LESSON VI.

~REGULATING AND REPAIRING.--(Continued.)~

THE SQUARE ACTION.

1. _The key_ in the square piano is subject to the same troubles as that of the upright, and requires the same treatment. However, the keys being much longer are more liable to cause trouble by warping.

2. _Bottom or Key Rocker_.--Unlike in the upright action, the jack is attached directly to the bottom; but, lowering or raising the bottom has the same effect in both cases. The screws regulating the height of the jack can be gotten at with a proper screwdriver. If you have to take out the key in order to regulate the bottom, first take particular notice of the conditions in respect to the operation of the jack on the hammer. Work the key slowly, to discover if there is lost motion. Decide which way the bottom must go and how far, so that you will not have to remove and replace the key more than once or twice to adjust it. In taking out the key, remove the board which is set edgewise over the keys immediately back of where the fingers strike, by taking out the screw at each end. Lift the hammer with the finger until the jack falls out of place; then by lifting the key off the balance pin it can be drawn out. The back check will sometimes rub so hard against the regulating b.u.t.ton that it will be bent somewhat, and must be adjusted after the key is replaced.

The bottom is often found to have shrunken; it rattles at every stroke of the key. This can generally be stopped by simply turning the back screw down until tight, which can be done without taking the key out.

This will rarely be found to alter the jack enough to cause it to fail to return to the notch in the b.u.t.t. After doing this, however, it is well to examine for such a condition.

A sluggish motion of the jack is often found in old square pianos caused by the swelling of the wood, at the point where the jack is hinged to the bottom, or by the center pin's becoming foul from oxide.

This will cause the jack to fail at times to operate on the hammer, especially in quick repet.i.tion. The key is struck with no response.

Take out the bottom entirely, and with the fingers press the sides of the bottom inward; at the same time, work the jack back and forth.

This will generally free it if the jack-spring is all right.

3. _Jack_.--As in the upright, the behavior of the jack depends entirely upon the surrounding members. A very common occurrence in the square piano is a broken jack-spring. This spring is concealed in a groove on the under side of the bottom, with a linen thread leading around the end of the jack and held fast by a wooden plug. If the spring is found to be long enough, drive out the plug, attach a new thread to the spring, and fasten as before. If a new spring is needed, one may be made by wrapping some small wire round a piece of music wire of the right size.

4. _The back check, hammer stem and regulating b.u.t.ton_ are subject to the same faults as their counterparts in the upright, which may be remedied in the same way. Bridles and hammer springs are not needed in the square, as the weight of the hammer, moving in a vertical direction, is sufficient to bring it to its rest position.