Sticky Keys? Humidity Is the Main Cause in Singapo

Published: 5/29/2026 9:54:09 PM   Clicked: 171

Sticky piano keys or sluggish return is one of the most common problems encountered by piano users in Singapore. The root cause is high humidity, which causes wooden keys and felt bushings to swell, increasing friction during movement.

When the front rail bushing felt absorbs moisture and expands, it grips the balance pin tightly, preventing the key from moving smoothly up and down. Additionally, swollen felt in the action parts such as the jack and hammer butt can also cause motion obstruction. To diagnose, remove the top door panel and observe whether the action parts corresponding to the sticky key return properly.

Repair methods vary by severity. For mild swelling, a technician can use a special key easing plier to slightly enlarge the bushing hole or use a hot iron to compress the felt. For severe swelling, replacing the front rail bushing felt or balance rail bushing felt is necessary, typically costing between S$50andS$150 depending on the number of parts replaced.

For pianos over 20 years old, key deformation may be caused not only by humidity but also by natural wood aging or insect damage. In such cases, full key bushing replacement or key planing and leveling may be required. The best way to prevent sticky keys is to install a dehumidifying rod and maintain ambient humidity between 50% and 70%. Once key sticking occurs, repair should be arranged promptly; otherwise, prolonged forced playing may permanently enlarge key bushings or deform action parts.