Chapter 3

A split in the sound board, in any style of piano, sometimes causes trouble due to the vibrating edges of the board coming in contact with each other. Insert the point of your screwdriver in the crack, holding it there firmly; if the rattling stops, the difficulty is discovered, and may be remedied by placing a screw or wedge in the crack, or a wedge of wood, cork or rubber between the sound board and iron plate or casing, if the location of the trouble permits. While this method seems a perfunctory one, it is nevertheless the best the tuner is prepared to do, for it is next to impossible to glue a crack in the sound board successfully outside of a regular factory or repair shop, where the instrument may be taken all apart and a new sound board put in or the old one properly repaired.

Sometimes the sound board gets loose or unglued at the edges, or the bridges or ribs come loose. Any part of the piano where there is vibration or loose material may become the source of the sympathetic rattle, as even parts of the case vibrate with the tones struck; so you must examine the panels, lock, hinges, soft pedal bar (in square), in fact all parts of the case and woodwork for the location of the trouble. Once found, the remedy will suggest itself. The greatest difficulty is to locate the cause. Very frequently this will be found entirely outside of the piano; a loose window glass, picture glass, lamp or other article of furniture in the room may respond to a particular tone or its octave. We have never found the sympathetic rattle in the action; it has rattles, but not of this character. Any other defect which may be found under this head will only require the exercise of a little mechanical ingenuity to suggest a remedy.

REGULATING AND REPAIRING THE UPRIGHT ACTION.

(Use cut of upright action for reference in following study.)

We will begin with the key and take up each part of the action in the succession in which motion is transmitted.

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 butt. 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 butt 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 flange 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 button.

6. _Regulating Button_.--This button determines the point in the stroke of the hammer where the jack flies off from the nose of the butt. If the button 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 button often wears until this trouble prevails. Lower the button 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 buttoner, will turn the screw.

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

7. _Hammer Butt_.--The felts and leather on the heel of the hammer butt wear out and must be replaced. The felt cushion, that is lowest and farthest to the left (see illustration), is the one that wears out first. The jack, in returning to the notch, strikes this cushion, and in time wears it away so that the jack in returning strikes the wood of the hammer butt, 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 butt of some cheap actions is not held in the butt 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 butt.

Hammers stick when the center pin is too tight in the flange. The bushing in the flange 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 bushing with a drop of water on each side so that it will penetrate the bushing. After this is done, the piano cannot be used for a day or two, as the water first swells the bushing, 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 butt, see that the hammer spring is in its place.

8. _Hammer Stem_.--These sometimes warp, split, crack, or come unglued at the butt 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, scrape 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 pass 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 button, 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 button 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 butt. 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 repetition. 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 button_ 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.

5. _Hammers_, when made of felt, will of course require the same treatment as those in the upright. In many old squares the hammers are built up of buckskin. If this becomes beaten down hard, it is well to cap the hammer with a new soft piece of buckskin, gluing only at the back ends.

6. _Butts and Flanges_.--A click just as the key comes up, indicates that the felt cushion, against which the jack rests, is worn out and must be replaced.

In all square actions the center pin, in the butt, is held by friction alone, but rarely gets loose; if it should be found loose, put in a larger pin.

The flange, shown in the cut, is what is called a split flange. By the set screw T, the jaws can be regulated so that they neither clamp the center pin so tightly as to make the action sluggish nor so loosely as to let the hammer wabble.

If the bushing cloth is found to be badly worn, it is better to put in new, which must be done neatly, or the result will not be satisfactory.

Hammer flanges, like all other wooden parts, shrink away from the screw heads and allow the hammer to drift to one side or rattle. While the action is in the piano, strike the keys to see if there are any that strike improperly. Mark the keys so as to indicate just what the trouble is, so that you will know how to remedy it when the action is out. If the hammers are set so close that they rub against each other, you may have to cut off a slight shaving of felt, but this is rarely necessary; for if properly placed, there is generally room for all; yet sometimes the expansion of the felt or warping of the shank makes cutting necessary.

7. _Dampers_.--The dampers in the square action depend entirely upon their weight for their efficiency in damping the strings and returning after being raised by the key. Often, after the key is struck, the damper will not return to its place and the string is undamped. This is generally found to be caused by the wire sticking in the hole through which it passes, the wire being rusty or bent or some foreign substance being in the hole round the wire. The bushing cloth in the hole may be in such condition as to retard the free passage of the damper wire, in which case the wire may be heated with a match and run up and down a few times through the hole, which will free it. The damper may not fall readily on account of a sluggish joint in the flange. Work it back and forth as far as it will go a few times; if necessary, take it off the damper rail and look for the cause of the trouble.

Damper flanges get loose on the damper rail and work to one side, causing defective damping and rattling. See that they are all tight, and in their places.

Damper lifter buttons sometimes hold the damper off the string. See that the top button falls so low that the damper lever does not touch it when the key is released. This is accomplished by altering the lower button. Examine the damper felts to see if they are moth-eaten, or have become hardened or in any way impaired. Notice the adjustment of the shade; that it is not too low or too high. The purpose of the shade is to prevent the damper levers from flying up; but it should be high enough so that the levers do not touch it when the key is depressed gently.

Defective damping is one of the most annoying conditions, and when one is employed to regulate a piano thoroughly and put it in order, he should see that no key is left in which this occurs. Strike each key and immediately let it up to see if it stops the sound quickly, or, in other words, damps perfectly; if it does not, find the cause and regulate until satisfactory.

8. _The grand action_ being, in principle, practically the same as that of the square and the upright, containing the same mechanism as is found in those actions, it is needless to give special instructions concerning it; as the previous work has given the pupil a thorough knowledge of the requirements of all actions, their common faults, and proper methods of regulating to bring about satisfactory results. Let us merely remark: Study thoroughly the behavior of every component part of each action that comes under your observation; understand what each part is for, why it is there, and how it works or should work properly to fill its office. Then regulate and try for results. If you have natural mechanical genius, a little experience will prepare you to do all regulating and repairing with skill and quickness.

MISCELLANEOUS REPAIRS.

A few miscellaneous difficulties, common to all styles of actions, are occasionally met with and need to be rectified.

1. _Broken Hammer Shank_.--Glue the ends, lay a nicely fitting piece of wood, well coated with glue, on each side and wrap with binding wire. If it is broken off up so close to the hammer as not to permit this, drill a hole through the hammer head in line with the center of the shank, with a small-sized screwdriver such as watchmakers use, and run the wire through this and around the shank, drawing it firm; glue as before; when dry it will be as strong as ever. When the shank is broken off close to the butt, the same treatment will sometimes answer, but the strain here is so much greater that it is sometimes necessary to put in a new shank. In fact, it is always better to do so.

2. _Flanges, damper heads_, and all small wooden parts are liable to break or come unglued. The watchmaker's screwdriver, the binding wire and the glue must always be at hand for these emergencies. These breaks are generally in places where wrapping is not permissible, and you are compelled to drill. Keep the screwdriver well sharpened and the drilling is easy.

3. _Ivories_.--When unglued, scrape the old glue off, apply glue to both surfaces and clamp with an ivory clamp or rubber band until the glue is firm. Apply the same treatment to ebony sharps.

4. _Leads_ in the keys and the dampers of the square piano get loose and rattle. Hammer them just enough to tighten; too much might split the key.

5. _Friction_.--Where different materials, such as wood and felt, would rub together they are covered with black lead to lubricate them. The point of the jack where it comes in contact with the butt, the toe of the jack which strikes the regulating button, and the long wooden capstan which takes the place of the extension and works directly on the under side of the wippen, which is covered with felt, are black-leaded. When a key squeaks and goes down reluctantly, the trouble can usually be traced to these places; especially to the wooden capstan, the black lead having worn away. Use powdered black lead on these parts.

There are many things in this kind of work that require only the exercise of "common sense." These we have omitted to mention, treating only of those things the student does not know intuitively.

QUESTIONS ON LESSON VI.

1. When a key snaps or clicks at the instant it is let up, give two or more conditions that might cause it.

2. When a key simply rattles, what parts of the action would you examine for the trouble?

3. When a key is struck and there is no response, what may be the cause?

4. Give two causes for defective damping in a square piano.

5. Give cause of and remedy for a squeaking key.

LESSON VII.

~THE STUDY AND PRACTICE OF PIANO TUNING.~

Before commencing the systematic study of piano tuning, we want to impress the student with a few important facts that underlie the great principles of scale building and general details of the art.