Hello and happy holidays!
On my upright piano, located in a large uninhabited apartment, some keys do not rebound because the escapement levers do not return to their position.
Disassembling one of them, the problem is due to the friction of the lever pivot; by trying to manipulate everything, eventually the movement became smooth and fluid enough that upon reassembling it, the situation was resolved.
It is obvious that temperature, humidity, and lack of use cause the problem, and the extreme solution would be to ream and restore all the pivots (as this group never fails to emphasize), but I wanted to ask if it is possible to intervene by lubricating (I saw a video where this was done!?): the important thing is that the lubricant does not cause irreversible damage, right?
What lubricant would be needed in this case?
Thank you and best wishes again.
