What makes a sound board crack?

[toskeye]

I have a 1909 Bluthner grand instrument in great musical shape. The case needs work. In considering my options for the finish work I might ship it off to a professional shop or do it myself in my garage. The shipping concerns me about risk of damage to the frame or soundboard... the dampness and cool temperature of the garage concerns me, too. What is the lesser of evils? or, my real question... what causes the sound board to crack?

thanks,
Eric

[Barrie Heaton]

Soundboards crack because of dryness this is common with older pianos as central heating was not common in most homes before the 1960s. In most cases the crack its self will not cause a loss in sound However, cracks can be a problem when they buzz

You need to keep a eye on the humidity to dry and the soundboard will crack however, to damp and you will get compression ridges which can be more of a problem in the long term as they can result in the sound board coming away form the belly bars and the sound board will buzz


Barrie

[toskeye]

Barrie. thanks. The dryness makes sense. I wasn't sure about the dampness. what humidity do you aim for... 50%?

What about temperature. could temperature at 40 deg F cause shrinkage and cracking.. or is there a recommended temperature range for keeping pianos?
thanks
Eric

[Barrie Heaton]

In most homes the hotter it is the dryer it is, in winter when the outside temperature drops well below freezing the humidity is very low outside and can drop to 0%

Houses in your country are very well insulated so you do need to monitor the humidity the ideal is 45% humidity with a temperature of 65 degrees but that is not comfortable to sit in for a long time


Barrie,

[Clavira]

TRY www.grandpiano.com.pl
Ask for quotation and you'll be surprised.
They're in Poland ( cheap !!!) but they work for many , much more expensive rebuilders in the UK.

GOOD LUCK

[toskeye]

I've just had a tuner review the piano and he is amazed at the excellent condition of the instrument. Some hammer and damper felts could be replaced, but the piano is in great condition... amazing for its age, actually. This is a relief! :D
I'm back to the subject of refinishing the case only... Does anyone know a real French polisher in Newcastle/Northumberland area? I can ship it there rather easily. Or in Aberdeenshire?
thanks
Eric