Pressure Ridges

[Ron Nossaman]

At 12:46 AM 3/19/99 EST, you wrote:
>I have a customer with a brand new Young Chang PG 150.  It has a nice big
>pressure ridge running the length of the sound board.  From what I have read,
>this will eventually turn into a nice big crack since the wood is crushed in
>this area.  I haven't officially taken a humidity reading, but the environment
>doesn't seem bad.  The piano isn't sitting in the sun or between two heat
>vents.  The temperature doesn't seem excessive one way or the other.  Should
>this be grounds for replacement by the manufacturer?  What are some of your
>opinions in this matter?
>
>David Porter
>St. Louis, MO 
>
>

Hi David,
I seriously doubt that it's grounds for warranty replacement, and so will
YC. The pressure ridge probably wouldn't be there unless the piano had been
through at least one humidity high that was considerably above the original
assembly RH. I don't know if YCs are compression crowned, or rib crowned,
but it makes a difference. The compression crowned boards form compression
ridges much more quickly and with narrower humidity swings than rib crowned
boards. In any case, you'll see lots of compression ridges in new pianos,
right off the truck, so I doubt that you'll have any luck with a warranty
claim. 

 Ron