Grand Regulation – part XXVIII

Step no 42: Check Damper Guide Rail, Ease or Rebush

All of the felts in a piano eventually ear out with age or use. One of the more overlooked areas of wear is in the damper guide rail. Perhaps the reason the guide rail, and for that matter, the entire damper system, is overlooked is because technicians hate to work on the dampers. Granted, the work is tedious, frustrating, and often a source of complaint from the pianist when it is not functioning correctly. However, the solution is to learn how to regulate the dampers, not to avoid it!

New pianos are much easier to work on since the felts are (or at least should be) in good shape. Before attempting to regulate the dampers, the first thing to check is the damper guide rail. One by one raise each damper head with your hand. Gently rotate it inside the hole and check to see if the damper wire has proper clearance. If it does not, then the hole will have to be eased. If it is too loose, then the felt must be replaced. Let us assume the worst and talk first about rebushing the damper guide rail.

Preferably this should be done in a shop, although it doesn’t have to be if you know how to do the job. Remove and store safely the action to the piano. Build a holder for the damper head / wires. I use a piece of firring strip 1” x 2” x 60”.  Blocks 3” x 3” x 1” are glued on to the ends of the fir strip. Holes are drilled about 1/2” apart, just large enough to fit the damper wires, but not so large as to let the dampers fall out if the fir strip is lifted upside down. Each hole is numbered and felt is glued onto the bottom of the 3” x 3” blocks.

Position the holder directly in back of the damper guide rail, letting it rest on the case, soundboard, strings, or whatever. Loosen all of the screws on the damper wire blocks. Carefully, making sure that the wires do not get bent out of shape, remove each damper head/wire from the wire block, pulling it through the guide rail and inserting it into the proper numbered hole in the damper wire holder. This is most easily done by starting at damper number one and working up. Spread the strings on each side of the screws for the damper guide rail, and remove the screws and rail. Either mark the screws for the holes, or else screw them back into their holes.

If the guide bushings were press fitted into the holes, removal of the felt will be easy. Where they were glued, take the damper guide rail to a drill press and punch the old bushings out. Make sure the holes are cleaned. Before the new felt is installed, I like to sand and refinish the guide rail to make it look as good as I can. Only the highest grade bushing cloth should be used to rebush the guide rail. Often this grade of cloth is not available domestically. Buy it in large sheets. Tear a strip from this sheet to the proper width to fit the guide hole. When the felt is inserted into the hole, the torn ends of the cloth will tend to mesh together at the seam.

Cut the cloth into 6” strips and taper one end so that it can be started into the hole. Insert the cloth through the guide rail hole from the top down. That is to say, the excess cloth will protrude from the counter-sunk side of the hole. Put a drop of glue onto the cloth on the counter-sink, and cut off the excess. I realize that not everyone likes to glue their damper guide rail bushings in. The only comment I can make is that those people must not have had the experience of pushing a damper bushing out the bottom of the hole while trying to ease a tight bushing! Use hide glue for this job. Reinstall the rail and dampers reversing the process used to remove them. Again, be careful not to bend the damper wires. When the wires are being inserted back into the wire blocks, they should move freely through the brass screw holder. This is a must when regulating the damper lift from the tray and key. If the wire does not pass freely into the hole, take a small drill bit (one smaller than the hole) and using the shank of the bit, not the cutting end, rotate the bit inside of the wire block screw hole, These brass inserts are just press-fitted and sometimes get turned a little when the screw is tightened against the damper wire. The drill bit will reposition this brass insert to allow the wire to move freely inside the hole.

Regulating the damper wires will be covered in the next two steps on the checklist. Now let us talk about what to do if a damper wire is sluggish and needs to be “eased.” To help find such ,tight bushings, one quick way is to raise and lower all of the dampers using the: sustain pedal. Any sluggish dampers will return slowly. Don’t come to conclusions yet, though, as sluggish dampers can be caused by things other than the damper guide rail. Also, although the dampers do return fast enough using the sustain pedal, they may still have excess friction at the guide hole.

Remove the action, and ...

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Grand Regulation – part XXVII

Step no41: Rebush / lube pedals and trapwork  

This step is divided into two parts. Part I deals with the lyre and pedals. Part II concerns the trapwork. So important is the pedal / trapwork system that it should not be left unattended, ever. Each time a piano is serviced, whether it be for regular tunings, or for minor or major repair and regulation, the pedals and accompanying systems should always be checked. As I sit down to a piano for regular tuning and maintenance, I always take a quick look inside to see how dirty the soundboard is, making note of how old the piano is and what model or size it happens to be. As I install the felt muting strips, I first depress the sustain pedal to raise the wedge dampers, to keep them from getting pinched while installing the muting strips. While depressing the pedal, I make note whether it squeaks, feels out of adjustment, or possibly if the entire lyre assembly is loose or needs repairing.

If anything seems to need attention, I correct it before I proceed any further. Only a minute is needed to wiggle the three pedals to see if they are loose. While down there, Iook over the lyre to check if any glue joints seem to be breaking loose, and also check the condition of the felt and leather of the trapwork. When the pedals are found to be loose, the lyre is usually in need of being removed. The exception is for Steinways, or any other make where the pedals can be removed independently of the lyre. One of my lesser desires in life is to have to reinstall a Steinway, so if I don’t have to remove it, I won’t! How one person can hold a lyre up off the ground, make sure that two lyre braces fit into their proper slots, and still have a free hand to join the lyre to the connecting plate under the keybed is a wonder to me. Anyway, proceeding with Steinways, remove the plate in front of the pedals, keeping the screws orderly so that they can be installed into the same holes. Disengage the pedal rods from the back of the pedals and pull the three pedals out. Each pedal can be worked on separately. Unscrew the plate on the bottom side of the pedal and check the condition of the felt bearing. New Steinways have a nylon sleeve instead of felt. The nylon seems to wear out quickly, so I only use good grade key bushing cloth when re-felting  these pedals. Cut a strip of bushing cloth, put some VJ lube on the area of wear, and tighten the plate back onto the pedal.

Of all the pianos I work on, the Steinways are my favourite for repairing the pedals. The above procedure can’t take much more than five minutes. I carry strips of bushing cloth precut to fit Steinway pedals in my tool case to speed this repair even more. However, if the pedals are accessible from the bottom of the lyre, the lyre must of course be removed. Before turning the lyre upside down, take the three pedal rods out and lay them somewhere in order. There is nothing like getting the pedal rods mixed up for wasting time and effort! Unscrew the lyre box bottom, marking it if needed to reinstall it properly. The most common type of system used in this kind of a lyre is where the pedal pin slides inside a wooden dowel. Again, before removing, number these dowels to insure that they don’t get mixed up. Also, check to see if the exposed ends of the dowels are level with the lyre box. If not, they may become noisy. Glue shims onto the dowel to bring it up level. Rebush the dowel if needed, and lube with VJ lube. After reinstalling the pedals, check to see whether they have proper clearance in the pedal slot. Cloth balance rail punchings can be used to adjust the pedal right or left as needed. Note that the felt trim in the pedal slot is not meant to guide the pedals.

I remember years ago working on my first lyre like this. I didn’t have the foresight to number the dowels before I removed them. Neither did I pay much attention to the fact that the holes in the dowels were not centred, but rather off-set along the length of the dowel. I reinstalled the pedals, put the lyre back on the piano, and ...

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Grand Regulation – part XXVI

Step no39: Adjust Key Stop Rail

  

This step is certainly one of lesser importance, although it cannot be overlooked. The key stop rail has, in my opinion, two functions. The primary function, though rarely needed, is to keep the keys from falling off the key pins when the piano is put on its side to be moved. Therefore, the key stop rail should be so adjusted that it is close enough to the keys to keep them from coming off the key pins when moved, with perhaps a little bit of play (maybe 1 /16” or so) between the tops of the keys and the bottom of the key stop rail. This amount of play should be checked on the black keys, as they will be a little higher than the white keys. If the piano is never going to be moved, it is certainly acceptable, possibly even smart with foresight, to remove the key stop rail altogether. This will eliminate problems associated with function number two.

Opposed to function number one, which is rarely used during the life of a normal home piano, function number two seems to crop its ugly head all too often. That is, to cause grief to piano technicians! The key stop rail is forever causing wasted time in removing it and reinstalling it. It often interferes with the other action parts. The screws which hold the rail in place become loose and rattle on the keys below, sometimes even causing the keys to stick. This rail must always be removed to retrieve foreign objects which have been caught between the keys, or when making adjustments in the key height or key dip.

The regulating technician must be very careful when installing this rail. Putting the rail too low causes it to bind on the keys, making the hammer line rise while throwing off the key level. On some pianos, the rail cannot be too high or the keys in the middle of the keyboard under the locking mechanism will bounce up and cause a noise when they hit the bottom of the lock! I have also seen cases where the key stop rail was too high, letting the sharps come up to high on the rebound. The back of the sharp hits the front of the fallboard and creates a knocking sound that is a hard one to track down.

The list of griefs that this rail can cause seems to get longer every year. Pencils, pens, pins, toothpicks, hairpins, etc. all too often get lodged between the key stop rail and the keys. I particularly dislike having to buy a special tool and to carry it with me just to unscrew the rails with the little brass nuts. And once the slotted brass nuts have been removed and the rail taken off, invariable one of the unslotted brass nuts which holds the rail in place from the bottom is so frozen that I can not get it off the threaded rod! Everyone seems to have their little pet peeves about something. Surely, one of mine is the key stop rail.

Section V: The Dampers and Pedals

Whenever I have attended or given a class on grand regulation, the dampers, sostenuto, trapwork and pedals are always last on the presentation. There never seems to be enough time devoted to these items, sometimes having to be eliminated altogether because of the lack of time. Since time and space is not a factor here, we will be discussing these last eleven steps in great detail. The order in which these last steps is taken is not nearly as important in section V as it was in earlier sections. However, I have tried to establish a sequence that is easy for me to follow.

This sequence will be: 


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