Freezing pianos/cracked plates

[John Lillico, RPT]

Hi Terry,

I've just sent a post on Heintzman and then saw your "Freezing Pianos" on Doherty. I'm beginning to feel like a history professor.

You may know that Sherlock and Manning were both employees of Doherty prior to setting up the Sherlock Manning company in London, Ontario. The new company eventually gained control of Doherty, sold their London facility to Spartan Radio and moved back to Clinton, long before my time.

>I have an early 1900's Doherty upright which I have extensively
>reconditioned, I'd almost call it a rebuild. I have two potential customers
>coming to look at it in the next few days. I have heard that Doherty >plates are somewhat fragile and that one should not raise them above >pitch when they are restrung. The restringing went well. The piano came >out very well.

I've not heard of "fragile" plates. Was it near pitch prior to your work? Is it structurally sound? If yes to both, you should have no problem.

>Up here in the hinterland, our temperatures are around minus 25 to >minus 30 celcius during the winter months.

>If I should sell this piano, what do you suppose the chances would be >that the plate might crack during the move from my shop to the home of >a new owner? I imagine that the pitch of the piano would increase >substantially being out in the cold for the hour or so that it takes to get it >to its new home.

No chance of breakage unless the piano falls off the back of the dog sled.
And rule out any chance of pitch increase through freezing weather.

>I suppose I could lower the pitch a half step or so for the move and then
>retune it afterwards.

Now, that idea would add strain to the plate and confuse the piano.

>Any comments or suggestions?

The most common cause of structural weakness results from glue failure. 
In my opinion, hyde glue, organic by nature, is prone to bacterial attack, accelerated by constant changes in dryness and humidity levels.

>Ron, who needs a cryogenic tank when one lives up here 8^)

Are you above the tree line?

John Lillico, RPT,
Oakville, Ontario, Canada