rusted piano strings

[mccleskey112 at bellsouth.net]

Thanks Ron. We, down south, live with high RH pretty much the year around 
and we have very little trouble with rusty  strings in homes that are 
normaly heated or air conditioned. We live with heat or air mostly the year 
dow here. It's the fresh air people that give us trouble. You know, the ones 
who have to open all the doors and windows on a nice day. In comes the RH 
and guess what happenas to the piano strgs. We get to restring another 
piano. Oh well, such is life.
Gerald McC
----- Original Message ----- 
From: "Ron Nossaman" <rnossaman at cox.net>
To: "Pianotech List" <pianotech at ptg.org>
Sent: Monday, February 18, 2008 6:29 PM
Subject: Re: rusted piano strings


>
>> If the entire room environment reaches the dew point...... No, this 
>> likely didn't even happen in New Orleans during/after Katrina.
>
> The entire room environment doesn't have to reach the dew point, only the 
> strings. That isn't that far fetched when the room cools down at night, 
> and both the temperature and moisture content of the air rise in the 
> morning before the strings catch up. For instance, if the piano was down 
> to 60° during the night, and is subjected to 70+° air at 60%RH or higher 
> when the heat cycles up and the lid is opened (or cover removed), the 
> strings are at or below the dew point of the room air. They won't have to 
> actually drip to be damaged, but it is an entirely possible situation.
>
>
>> The only way dew point could be reached on piano strings would be if the 
>> room was cold and somehow was rapidly heated AND the humidity was raised 
>> to a very high level.
>
> Like turning on the heat and filling the room with people as the piano 
> lags 20° behind, or opening the doors to a room air conditioned to 73°, 
> and letting in 85° 75% outside air in? Again, not that far fetched.
>
>
>> Now it certainly could happen if maybe the piano was stored in an 
>> unheated building in a cold climate and was then moved into a warm room 
>> of moderate humidity - then, yes, you could actually have water 
>> condensate on the strings.
>
> You don't have to be able to see the water for it to be there, and I 
> expect it doesn't take much.
>
> Just an observation from the cheap seats.
>
> Ron N