The Piano Keys
There are 88 keys on a standard grand piano.
If the keys feature original ivory, our expert ivory keytop restorers go to work. The vintage ivory keytops are sanded, cleaned and polished to create a smooth surface and return them to a brilliant, like-new look. Often the original keytops have loosened from years of playing and are glued securely back into place. If new keytops are required or requested we use only the highest quality acrylic materials. Old key sticks usually come into our shop in a very dirty state. We clean and sand each individual key stick to ensure a smooth feel and a clean action. If the key sticks ‘wiggle’ this creates an unstable feeling keyboard that does not instill confidence in the player. Key bushings are checked to make sure they are tight enough to hold the key firmly, yet loose enough so they do not bind against the key pins.
The key end felt is evaluated and about 90% of the time full replacement is required. The key end felt pushes against the damper underlever and raises them when a note is played. Over time this can become moth-eaten and matted down, resulting in dampers that fail to lift fully. The keybed felt on which the back ends of the keys sticks rest goes through the same process and evaluation.
Leveling the Keys
Many vintage pianos have keys that are no longer level. An uneven keyboard can be a constant frustration for a pianist of any skill level. To level the keys we remove the key sticks and precisely level the entire keyboard. This is done by using paper punchings of various thicknesses that adjust the key to the proper height. A punching made of felt is then placed over the paper to help absorb the impact of the keystroke. The keys are then checked to ensure they are at the correct height in relation to the piano’s fallboard. Working from the outside in, each key is positioned to create the correct level of key dip. After the keys are leveled, the keys are played thousands of times to tamp down the felt and paper punchings. Final adjustments are then made. This seemingly simple process requires precision and careful measurements to allow for an even keyboard and the right level of key drop.
The Art of Tone Regulation
Creating the Desired Sound
Historic piano hammers were first constructed out of paper and small pieces of leather. This early design lacked power and durability. Modern piano hammers are pressed out of dense, high-quality felt. When brand new Steinway hammers are ordered from the Steinway Parts Department they are most often very soft and misshaped. To achieve the correct shape for maximum power and tone they are filed, shaved and carefully re-shaped. This is a process that to varying degrees must be carried out on all factory new hammers prior to use. Due to the softness of new Steinway hammers, they produce an overly mellow tone with insufficient projection and sustain.
To achieve the desired tone, specialty felt hardening substances are carefully applied. This adds power and brilliance to the resulting tone. After the hammer hardening process, our technicians even out or mellow the tone by carefully voicing and needling the hammers. This process is an extensive one that truly brings out the very best an individual instrument can be. When completing a piano for a client, we can craft the tone of a piano to be as bright or mellow as the pianist desires.
Chupp’s Piano Service technicians understand proper substance mixture and application, proper voicing and needling techniques and the myriad of other adjustments necessary to bring a piano up to its full potential. These skills were learned at the Steinway factory and from continued training with legendary Steinway Factory and industry leading technicians.
The tone regulation process is one of the most essential parts of any service work done on your piano. Bringing out the tone that the pianist desires is only possible with proper voicing techniques. We have the experience and expert training to do just that. Tone regulation is a true art, that when executed properly, brings out the very best a piano can be. This process is where a piano is elevated from not just a mechanical marvel, but to a beautiful musical instrument.
Weigh-Off – The Art of Touch Weight
The keys are then weighed off to exacting specifications. Once the action stack is rebuilt with new parts and initial regulation is completed, the weigh-off technician begins taking their measurements. Highly accurate brass gram weights are used to measure both the down-weight (the amount of weight needed to depress the piano key) and the up-weight (the maximum amount of weight the key can lift during its return to its resting point). Traditionally on a Steinway & Sons Grand Piano, the down-weight is around 50-52 grams and the up-weight comes in at around 28-30 grams in the center of the piano. Each and every key is reweighed during this process to ensure an incredibly responsive action that allows a pianist to fly across the keyboard. This step is one that is often ignored but is, in fact, one of the most vital components of a full action restoration. [Watch a short video demonstrating this process, here.]
Adjustments and Action Regulation
After the entire action has been assembled and checked, final adjustments and regulations are made. The regulation process is truly where the voice and feel of the piano blooms. The hammers are aligned to the strings to make sure they strike the string at the precise point needed. The capstans are adjusted, the wippens are aligned to the knuckles, the let-off is set on the end hammers, the let off and drop is finalized, the spring tension is adjusted and much more. This entire process ensures the correct touch and maximum responsiveness.
Proper action regulation is truly an art and is one of the final and most important steps of the piano restoration and rebuilding process. This job is one that takes time, talent and a dedication to the craft. Our technicians are highly trained by the best in the industry and have the experience needed to craft an action that fits your performance needs. This is just some of the work that we do on every single restored piano we work on here at Chupp’s Piano Service. Our processes are time-tested and proven to produce a piano that plays at its optimum potential.