So, we asked our repair technician if these are repaired or replaced. We had an inkling that they would be replaced, because it isn't really possible to "repair" such a small piece of foam or felt. Indeed, they are always replaced. When? Well, they are replaced when you send your flute in for a complete overhaul. Why is this? It's because in an overhaul, the keys need to be removed from the flute so that they can be polished on a buffing wheel. Since the entire key (including the tail) gets polished, the felts and foam are removed. Then, they are replaced in the process of putting the keys back on the flute! In general, the felts and foam are left in tact during the light polishing during a COA. However, a felt or foam tail can always be replaced if necessary from wear.
|Finisher adding felt to keys. Yellow arrow points to finished felt on key.
|Orange arrow points to foam on key.
|Red arrows point to foam, yellow arrows point to felt.