Rusty Strings (was: Re: Chemical Damage to D-Chaser Unit)

[Bill Ballard]

At 5:51 PM -0600 11/12/01, Bobby R. Sims wrote:
>Hello,
>
>I am not a chemist but I do work at a water treatment facility.  When tap
>water is chlorinated is then has ammonia added to it to stabilize the
>disinfection of the chlorine.  The chlorine is about 3.0mg/L (ppm) when it
>leaves the plant I work at.  It will loose some in the distribution process.
>Maybe water filtered through carbon filters such as canister filters for the
>refrigerator would be somewhat better than tap.


Sorry about the premature release of the above quoted material. I am 
very interested in how successful that stabilization is, because if 
it isn't, the chlorine could immediately become volatile again. 
Ammonium Chloride was the main active ingredient on the hardware 
store shelf I looked at. I'm not a chemist either but I'd guess the 
reason why Chlor- turned out to be Chloride instead of Chlorine, is 
because the Ammonium is doing its work.

Any report you could make on the success of ammonium in binding the 
chlorine under what might be a aggravating conditions (heat of the 
bar, as well as any electrical field around heating element) would be 
a welcome contribution. This situation may be more common than we 
think.

In that regard, I had a very good conversation with Roger Wheelock 
(Dampp-Chasser) who posted here earlier today. He did a very 
persuasive presentations of the situation, as well as posting advice 
on a regular service plan to insure that the system be running 
healthily.

There still remains the situation of rust damage to the strings and 
pins. I'll re-post the situation there:

At 10:47 PM -0500 11/9/01, Bill Ballard wrote:
>The piano tuned fine: I would have been the first to complain about 
>string friction. The strings do not break. The treble third of the 
>action is not in the grip of corroded center pins. There is no 
>damage to the wood finish, just steel parts.
>
>The fix is simple. I already have the replacement heater bar, and 
>I'm going to scrub the dust off the treble wire and the tpins. I'm 
>confident of the wire (because it still tunes smoothly and doesn't 
>snap), But I'd like to mic it after scrubbing it. What I do know is 
>that whatever wire diameter has been lost to corrosion is not enough 
>to fatally increase the wire's tension.
>
>Has anybody run into this situation before? Is anybody familiar with 
>the chemistry at work? Is my suspicion that water vapor is the agent 
>here, completely baseless?

In other words, is a baffle thumbtacked to the underside of the 
keybed and 15-18" above the floor level HM-2, in the best location to 
deflect upwards water vapor from running the treble wire just above 
the keybed? (I know that between us all on the list we've installed 
at least fifty DC systems.)

Thanks to all for your contributions.

Bill Ballard RPT
NH Chapter, P.T.G.

"We mustn't underestimate our power of teamwork."
     ...........Bob Davis RPT, pianotech '97
+++++++++++++++++++++