The soundboard is a large thin piece of wood. It is common for cracks to develop. The expert opinions on soundboard cracks vary dramatically from "this crack has ruined the piano" to "unless the crack is causing major problem, such as a tuning issue or an annoying vibration, leave well enough alone". And everything in between.
The severity and nature of the issues caused by a crack, in the soundboard, depend on the size and type of crack. When a crack develops, replacing or repairing the soundboard is the best solution. Both options are expensive and usually exceed the value of the piano.
If the crack is minor in nature, there is another option. Stabilizing the crack, by inserting high-tech glue, in the crack, with a syringe, to help stabilize the crack. This reduces the risk of the crack spreading and reduces unwanted vibrations. The process is relatively inexpensive, especially when compared to the cost of replacing a soundboard. The current list price for this service includes material and up to 1 hour of labor. Additional labor and materials charges may apply if there are several cracks, or if there is extra labor to move the piano, to complete the process.
This technique can also be used for minor bridge cracks.
