As your Piano Tuner Wilmington DE , I am frequently asked about the cause of sticking piano keys. A frequent follow-up question is, “Can I fix it myself?” There are several possible causes of a sticking piano key. Our previous post covered some of the causes that are easiest to explain. This post will cover some of the causes that are a little more difficult to explain, and our next post will complete the explanations.
One cause of sticking keys is the drying out of the wooden action parts. One of the last procedures when piano is made, is the weighting of the keys. Small cylindrical weights are added so the the keys return properly. The overall measurement automatically includes the weight of the various wooden action parts. A problem can arise as the piano ages. The various wooden action parts lose moisture, and end up weighing less. If the overall weight gets reduced significantly, then the keys do not return. Usually this happens only on older spinet pianos. The solution is for the piano technician to add a small lead weight to the back of each key.
Another cause is wear on the key bushings. Treble keys on small pianos usually have a significant angle at the middle of the key. They do not run straight back toward the piano action. The reason is that the front of the keys must all line up alongside each other. There cannot be gaps in a keyboard. The back of the keys, however, must align with the action parts, which usually are off to the right on a small piano. As a result of this design, the middle, or “balance rail” key bushings get worn quickly due to the lateral forces when the keys are played. When these key bushings get worn, they get indented, causing more friction so that the piano keys get stuck in a down position. The correction is for the piano technician to replace the worn key bushings.
Our next post will explain even more complicated processes that cause sticking keys. If you have any questions about pianos, please let us know. We are your Wilmington DE piano tuning experts. We also provide professional piano services in Philadelphia, Southern NJ and Eastern Shore MD.