Hi Dale,
Glad you like the Villa-Lobos/Ginastera music. It is still some of my favorite all time.
I'm going to paste part of a class handout that will give you an idea of my upright protocol. One of these days I hope to put some of these classes into a Blog format, with the handout plus the illustrations (slides from the Powerpoint).
The Practice Room Upright - making it into a musical instrument and making it last
Las Vegas 2010
Fred Sturm
Upright pianos, in the practice rooms in particular, but also elsewhere in a music department, are often neglected, and allowed to become badly worn out embarrassments that are incapable of making music. Even in the best of situations, we often do little to uprights other than tuning them, and focus our efforts on grands. But uprights play a very important role in music education: they are used by accompanists, by music students acquiring piano proficiency, by music theory and composition students to try out their work, and often enough by piano majors and by professors. They can be made into relatively refined musical instruments by using focused and organized techniques. These techniques obviously can be applied to any upright piano, but they have been developed in the high use environment of a busy music department, so there is an emphasis on ways to make the parts and workmanship last as long as possible.
In some cases, I will be mixing techniques in this class, depending on whether the piano is relatively new or fairly old and worn. The goals are the same, but sometimes the techniques vary.
The first focal point is the keyboard, which must be virtually friction free, yet very firm. This is of utmost importance to both the feel and function of the piano action. Wobbly keys that knock against pins (or, in extreme cases, against neighboring keys) make a piano feel worn out and imprecise. Tight bushings or balance holes cause friction problems leading to sluggishness and a heavy touch. We will look at fitting new key bushings and balance holes to the key pins, and also re-fitting old, compressed bushings (when old bushings are too worn to be refit, they will need to be replaced, and then are treated as new bushings).
Friction is of utmost importance in longevity of parts and workmanship. In an upright, the main places we lubricate in an action are key pins and key bushings, capstans and wipp cushions, and spoons/lift rod and damper lever felt. Hammer butt leather/jack top and jack tender/let off are less important than corresponding points in grands, and more difficult to get at, so we generally omit them.
When it comes to tone quality, the same principles apply to both uprights and grands, though we don't usually split as many hairs with uprights. In fact, many factories and technicians omit the basic steps of traveling, squaring the hammer to the string (burning shanks), mating hammer to strings, and needling hammers. These steps can and must be done to achieve good results. The techniques are quite similar to those used on grands, but must take into account the fact that the damper action is in the way, and that the hammer flange screw is less accessible.
I will include some shortcut procedures using steam or chemicals (alcohol, water and softener in controlled combinations) for cases where time is too short, or where hammers are too hard to needle. But needling is always preferable.
Procedures:
Keys: key pins, balance holes, key bushings, capstans
Key pins:
As a first step, key pins should be examined to be certain all are smooth and plating is in good condition. Nicked or corroded key pins should be replaced. Assuming reasonably smooth key pins, I recommend lubricating them with McLube 444 (alternately ProLube). Use a pipe cleaner with about one inch bent back on itself, dip into the lubricant, use it to apply lube to both sides of each key pin in turn (usually one dip will last 20 or more pins). This goes very fast, less than five minutes. Polishing is also possible, but takes a good bit longer and more effort.
Balance Holes:
The balance holes of the keys should be sized to the balance pins. I won't go into holes that are too large here (see my article in the December, 2007 PTJ - also for additional details). For holes where some are too small, use a parallel fluted reamer .001" larger than the balance (.147" for the most common pins, other sizes as needed. McMaster-Carr http://www.mcmaster.com/ is a good source, about $15 each). A rubber band can be wrapped around the smooth shank to act as a handle. Simply insert and rotate (twirl with the fingers), a second or so per key. Follow with the tapered easing tool, inserted through the key button, first establishing how far the tool needs to be inserted on a test key, then fixing the fingers on the tool so as to limit penetration to that depth, and do all keys.
Bushings, resizing:
Old bushings, if they are mostly compressed and not too worn, can be resized using steam to swell the felt, then cauls in a hot iron to size it precisely. Keys are placed in key clamps. A steamer is used to apply enough steam to swell the felt, not enough to loosen the glue joint. There is usually plenty of wiggle room between enough to swell and the amount needed to loosen glue. Steaming is followed immediately by insertion of a heated, thermostatically controlled bushing caul of the correct size. I use a Conair portable steamer (intended for clothing), about $35 at Target. About 2 - 3 seconds total per bushing suffices (this is not enough time for glue to soften and penetrate the felt). Keep the steam source moving along the row of bushings, watching the results, and repeat if necessary.
I do a key clamp worth of one bushing (front or balance) at a time, and follow with the caul, a quick insertion of less than one second. A corner of the caul should be inserted first, then align it straight in the bushing. When all bushings have been treated this way, I go through each bushing with the caul again, about one second each. Note that the balance holes should be sized after steaming the bushings, as the steam may also swell the wood.
Bushings, lubricating and sizing:
Key bushings should always be lubricated. I prefer powdered Teflon, but a liquid like ProLube or Protek CLP can be substituted (McLube 444 should not be used for felt, as it will harden in the felt and make it stiff, causing knocking). When rebushing keys, powdered Teflon can be applied to one side of the felt before gluing (I prefer Bill Spurlock's methods and cauls). For new, un-lubricated bushings, Teflon powder can be applied to bushings using a pipe cleaner. Application should be followed with a heated caul, as the fibers of the pipe cleaner disturb the fibers of the bushings and may create temporary high friction. Ironing sets the surface fibers, makes them smoother, and sizes them precisely.
Applying Teflon powder and ironing is standard procedure for any new piano, along with checking for and correcting tight balance holes. This eliminates common friction problems, and adds considerably to longevity of the "new feel" of the piano.
Done on a regular basis, every five or ten years or so, the process of lubrication and resizing can take less than an hour, and contributes a great deal to the foundation of the action, its feel and responsiveness. With experience, the keys can be dropped back onto the key pins with no need to do more than a bit of spot-checking for sizing issues.
Note that eventually the bushing felt will become hard, especially if it has been over-heated with cauls that are too hot. At this point the felt will need to be replaced, even if it can still be re-sized, because there will be a knocking feeling of bushing against pin as well as noise.
Action Lubrication Points
While the keys are being attended to, and the pipe cleaner is wet with lubricant for the key pins, the capstans can get a quick application of the same lubricant. (If the capstans are dirty and/or badly tarnished, a quick application of Flitz polish with a rag, followed by rubbing with the same wet rag, then polishing with a dry rag, will quickly address this).
A pipe cleaner or brush can be used to apply Teflon powder to the wippen cushions: simply turn the action upside down (tops of action brackets on table), hold in place with one hand, and apply the powder with the other. Rub the powder in with a finger.
Teflon powder can also be applied to the damper lever felt, covering the areas contacted by the spoons and the lift rod, using a pipe cleaner. I usually just lay the action down, hammer rail side on a table. If there is a large enough gap between the damper lever felt and the spoons and lift rod, simply insert the pipe cleaner and apply the powder. Otherwise, a straightedge of some sort can be used to hold the dampers out of the way, pressing on the wires just above the levers.
It is also possible to lubricate the metal of the spoons and lift rod, again using a pipe cleaner. I often do both for good measure (it takes very little time). If I use McLube 444, I try not to get any on the felt. I use a piece of aluminum flashing as a shield between the felt and the pipe cleaner. (A little bit won't hurt, as long as it's on the surface and doesn't saturate the felt).
If the letoff buttons are somewhat old, and indented so that regulation is problematic, remove the rail (usually just loosen the screws holding it to the brackets, and slide out to one side). Dress the punchings with a brush, or sand lightly, then apply water lightly with a brush and iron flat with a clothes iron. Brush on some Teflon powder and rub in with a finger. Replace the rail. I have not found an efficient way to deal with the jack to butt leather interface, unless all dampers are removed for some reason.
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Fred Sturm
University of New Mexico
fssturm@unm.edu http://fredsturm.net http://www.artoftuning.com "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
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Original Message:
Sent: 04-13-2015 17:09
From: Dale Probst
Subject: odd "pedal" squeak
Hey Fred,
Great post, as usual, would you care to share your protocol that you have developed?
Off topic: listened to your cd Piano music of Ginastera and Villa-Lobos again yesterday, absolutely gorgeous sound!
Best,
Dale
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Dale Probst
Registered Piano Technician
Wichita Falls TX
dale@wardprobst.com
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