<html> <body> Petrification involves mineralization, usually water-born.  Usually underground where aerobic bacteria can't thrive. A failed sound-board has more to do with structural compression damage to the wood fibers.  Ie ten year old Chinese pianos with coastal spruce where the fat grain has dried out and the board collapsed.  The wood has lost its "stiffness" and absorbs vibrations much more than it did when new.  To a lesser degree this happens to old boards.  Sometimes re-ribbing can revive a board.  Shimming cracks that divide a board is another time-tested method. Andrew Anderson At 12:57 AM 12/5/2005, you wrote: <blockquote type=cite class=cite cite="">Thanks for your reply Terry,   So if I completely understand what you said, it is impossible for a soundboard to become petrified because the petrification appears after thousands of years.   But I'm sure someone talked about this to explain why an old sounboard could not remain as powerful as a new one.   Wasn't it you BTW who said that in a past topic?   Q.</blockquote></body> </html>