How to eliminate grooves on the upright piano hammer felt head DIY?

[themaximillyan]

Max demonstrates how to do this, although the final result of the repair is not fully shown in this video, sorry. The end result of this operation is the complete elimination of grooves on the felt part (head) of the upright piano hammer, as well as an improvement in sound quality.

Max uses various nail files for this work, with the most convenient being Polish and Soviet ones. Some technicians use fine-grit sandpaper or foam, however, these materials remove a significant area without limitations. Once treated, the hammer should have a pear-shaped form as intended by the piano manufacturers, and should not have any grooves. Grooves appear over time due to the wear and tear of the instrument and the loosening of the wool felt caused by striking the strings. In some cases, up to 1 cm of the wool felt plane can be worn, causing the string to sound muffled and dull due to additional damping. This can make it difficult for a pianist to fully utilize playing techniques, such as staccato.

It is recommended to focus on the striking surface of the hammer and use several female nail files to avoid risking it there. Therefore, if there is an opportunity for self-repair, do not procrastinate, and sharpen your hammers yourself! Take your time, work slowly and carefully, and the new sound will delight you with new timbral colors of yours upright piano.