One of the first things to consider about any used piano is tuning stability. Ask these questions; Can the piano be tuned? Will the piano hold its tune?
One major factor in the answer is the Pinblock.
• A pinblock is the part of the piano that holds the tuning pins. It must:
1. Exert pressure on the tuning pin to keep it from slipping.
2. Allow the tuning pin to be rotated smoothly during the tuning process.
3. The best material for pinblock construction is a very dense hardwood (ex. maple, beech).
4. The pinblock must be constructed with multiple layers of hardwood, bonded together at cross-grains to hold the pin. This process is called lamination.
5. To hold the tuning pin tightly over the years, the block must also be protected from the problems caused by daily humidity changes.
Many antique piano pinblock’s have “lost their grip” on the tuning pin and can no longer hold the tension created when the string is pulled up to pitch. This is caused by the constant pressure always being pulled against it and the changes in humidity that have occurred over the years on the wood. The problem of lost tuning stability can be repaired on most older antique pianos by replacing the pinblock altogether or in some cases by replacing the tuning pins with a larger diameter tuning pin. The second option is more common with upright pianos where the cost of replacing the pinblock is not always cost effective. Either way, the piano can be repaired, and be able to hold its tuning again.