The touch of a piano can vary considerably from brand to brand and model to model. Spinet pianos tend to feel light and delicate. And, sometimes grand piano keys feel heavy and slow. These moderate differences in touch are part of normal piano engineering. Manufactures typically use a common set of parameters when producing pianos.
Over time, dirt, dust, wear and tear can change those specifications making the touch of your piano keys feel heavy and sluggish. Cleaning, lubrication and action regulation will usually restore, and often make better, the original touch and feel of your piano’s keys.
Occasionally, cleaning, lubrication and action regulation are not enough to make your piano keys feel lighter. Careful examination can sometimes expose a touchweight problem. The good news is that this can be corrected which results in a piano with a much more consistent and controllable touch.
Older Steinway pianos from the 1920’s and 1930’s can have a unique problem called Verdigris. This green “gunk” is caused by a chemical reaction between the metal center-pins and chemicals used to treat bushing cloth. This will make the piano keys feel heavy and very sluggish. And, can become so severe as to render the piano almost unplayable. Although there are some temporary solutions to the Verdigris problem, the only real permanent one is to replace all action parts with new – a costly endeavor.