The following idea is purely speculation however it occurred to me shortly after learning the facts. The information comes from a retired gypsum company troubleshooter.
Roughly 10+ years ago there was some importing of sheetrock from China that had a very high sulpher content (a result of different standards of manufacture between U.S. and China, and not tested for here until after the debacle). Most of this sheetrock went to the southern (very humid) states recovering from disasters.
The problem was that when the gypsum was exposed to high humidity, it began offgassing corrosive fumes (hydrogen sulfide or sulfate or some such stuff...don't recall the exact terminology, but it basically created sulfuric acid) that reacted with anything made of copper, destroying copper pipes, electrical wiring, etc. Ultimately these houses had to totally gutted inside and rebuilt with "proper" sheetrock.
So, not being a chemical engineer I don't KNOW if this could have had an effect on lead. Does anyone who knows chemistry know if this is at all possible? Or could offgassing of other chemicals such as in carpeting, flooring, or plastics, etc when subjected to high moisture, cause any if this lead corrosion. It does seem to be largely found in consistently humid areas.
Curious.
Pwg
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Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com------------------------------
Original Message:
Sent: 06-03-2019 08:07
From: Karl Roeder
Subject: Key lead corrosion and acetic acid
I only have the most rudimentary understanding of acetylation so I don't know if it's possible to do lighter and heavier applications. Perhaps there is a way to produce something that works as a piano key without hardening the wood to the point of an Accoya door sill. I think I will try and check with Bob Marinelli to see if he can shed some light on the subject.
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Karl Roeder
Pompano Beach FL
Original Message:
Sent: 06-02-2019 17:58
From: Jim Ialeggio
Subject: Key lead corrosion and acetic acid
maybe kluge has a "tropical" option you can order in a new keyset. Sure sounds acetylated
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
Original Message:
Sent: 06-02-2019 14:51
From: Karl Roeder
Subject: Key lead corrosion and acetic acid
Mr. Blees,
I didn't drill the leads out. I used a set of Dead-leader pliers from Acousticraft. With the corroded leads this was challenging as they were far less inclined to slide out of the holes. For a goodly number of them I ended up using a slide clamp to squeeze the handles when two hands weren't able to generate the pressure needed. This particular set of keys is from 1993 and had lead in all 88 keys. All of the lead was compromised to some degree. Without the lead I can still smell the acetic acid even in my well ventilated shop.
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Karl Roeder
Pompano Beach FL
Original Message:
Sent: 06-01-2019 22:16
From: Willem Blees
Subject: Key lead corrosion and acetic acid
Karl
As you know, we encounter a lot of lead corrosion here in Hawaii. I can't say for sure if the keys are from Kluge, but I have never smelled anything when taking an action back to my shop.
I wonder if the smell is coming from the wood, or from something else. When you drilled out the leads, did you notice a string smell?
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Willem "Wim" Blees, RPT
Mililani, HI 96789
Original Message:
Sent: 06-01-2019 10:15
From: Karl Roeder
Subject: Key lead corrosion and acetic acid
Greetings learned colleagues.
I find myself yet again dealing with rather severe key lead corrosion in a Kluge keyset. Here in ultra-humid S.Florida I see this problem fairly often. While I do see it in older pianos particularly those exposed to beach environments I find some of the worst cases are relatively new <30yrs Kluge keys in climate controlled spaces. When transporting the latest action to my shop I noticed a strong smell of acetic acid in the car. Strong enough that I had to open the windows a couple of times on the ride to the shop. In other threads on this topic I've seen the natural presence of acetic acid in all wood mentioned as a cause of corrosion. The smell associated with this keyset seems too strong to simply be from the spruce alone. In trying to chase down possible sources for the smell I came across a lot of references to acetylation of wood being used in industrial settings to stabilize wood and reduce it's dimensional variation due to humidity.
I am now left with two questions. Does Kluge use acetylation to stabilize the spruce keys? And more importantly; How can I prevent the replacement leads from corrosion? I am contemplating sealing the keys with shelac to keep the acetic acid vapors inside the wood but am hesitant because I've never seen a set of keys with visible finish or sealer aside from on the key buttons. I'm also considering sealing the leads with rustoleum rust reformer prior to installation. I'd very much like to hear others thoughts on this Below I'll try and include a couple of links to interesting articles on acetylation.
https://wfs.swst.org/index.php/wfs/article/viewFile/1584/1584
https://ir.library.oregonstate.edu/dspace/bitstream/1957/1651/1/FPL_1593ocr.pdf
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Karl Roeder
Pompano Beach FL
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