I have been told by my tuner that our old family piano has a cracked frame. Just how serious is this and can anything be done to save the piano?
The piano frame is made of cast iron which needs to be very strong to hold the enormous tension exerted by the strings but is also quite brittle. Cracks can appear if the piano is dropped but can also be due to defects during the manufacturing process which only become apparent years after the piano is out of its warranty period. Generally, it is an unfortunate occurrence and you will need to monitor it carefully to check if the crack is increasing in size. Often, there are no ill effects at all but if the tuning in the area of the crack seems to slip rather more quickly than it should, it might be prudent to ask your tuner to lower the pitch to reduce the strain and improve the tuning stability. Cast iron cannot be welded but there is a process available which can repair a piano frame to its former strength. However, this is not a cheap option and should only be considered if the piano is of sufficient quality to justify the expense of removing the frame to be shipped to the repairer. If your piano is an upright then it is almost certainly not worth considering the repair but before rushing out to buy a new one, just be sure that the crack in the frame really is affecting the piano.