<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: R,C&S question JD</title></head><body> <div>Here's a picture that shows clearly the effect of compression at the glue line.</div> <div><br></div> <div>Full size at: <http://pianomaker.co.uk/temp/swollen_soundboard.jpg></div> <div><br></div> <div><br></div> <div align="center"><a href="http://pianomaker.co.uk/temp/swollen_soundboard.jpg"><img src="cid:p0624080ac3c2795588da@[10.0.0.1].1.0"></a></div> <div><br></div> <div><br></div> <div>This is a soundboard (from a Dresden maker of no great repute) that has been kept in an environment of over 90% relative humidity for a long time.  The bridge screws on the middle rib are about a foot apart and the gap that has formed is about 1/10" on the middle rib.  At the top surface there is no cracking, ridging or checking of the varnish, and a smooth hump to show what has happened underneath.  The ribs are curved.</div> <div><br></div> <div>The main problem here is the glue and in fact the whole piano is a demonstration of what can happen if inadequate attention is paid to glue quality among other things. (Blüthner had so many problems with their gluing in the early days that they finally resorted to turning a few hundred pretty screws through the soundboard to keep the ribs from falling off.)</div> <div><br></div> <div>If the glue had not failed here, it is quite likely the soundboard would be in adequate working order and good-looking too.</div> <div><br></div> <div>JD</div> </body> </html>