A method to verify the extent of de-lamination in a grand piano pin block…. put chalk in the crack, block off one side of the pin block and blow a puff of compressed air in a tuning pin hole and observe to see if the chalk is blown out! This is mildly interesting as the pin block is in a brand new Chinese grand piano. NOT A Yamaha!!!!
![](https://s2.save4k.ru/pic/uXAfwpcbCG8/mqdefault.jpg)