Hi Horace,
Years ago there was no standards for coal burning
fire places in homes. and industrial smog was the norm in
industrialized cities. This pumped a lot of sulphur into the
atmosphere, combined this water vapor, and it will produce sulfuric
acid ( H2SO4). The copper component of brass combined with the acid,
produced anhydrous copper sulfate (CuSO40, hence the green gremlins.
This would also help to explain why these pianos work well on the
Canadian Prairies, where there was no industrialization back then.
Unless we know the environmental history we can only guess.
Regards Roger
At 03:12 PM 08/01/2011, you wrote:
>Hi, Fred,
>
>At 05:11 PM 1/7/2011, you wrote:
>>On Jan 7, 2011, at 5:59 PM, Horace Greeley wrote:
>>
>>>The buckets into which parts (flanges only, unless the piano was
>>>being "tropicalized") were dipped were filled with melted paraffin
>>>wax, which was not mixed with tallow.
>>
>>
>> If this is the case, no other "contaminants" besides a bit of whale
>>oil, that makes the verdigris question quite puzzling. One thing that
>>"paraffins" have in common is non-reactivity. They don't really
>>combine well with other chemicals, though they burn readily. Seemingly
>>they are nearly inert chemically, so it seems unlikely they would
>>become gummy with age. Hmmm... Unless the "paraffin wax" was not well
>>refined, and had impurities that led to the long term problems. Or
>>somehow humidity and atmospheric contaminants somehow interacted in
>>the environment created by paraffin impregnated wool.
>
>These are all really good points.
>
>It's never made any sense to me that the paraffin, of itself, would
>create the problem; there needed to be some other reactants in the
>process. The best guess(es) I've ever heard are very much along the
>lines you suggest...i.e., that there is usually some interaction
>with the overall environment. When that is coupled with the odd
>mixture of things at play - paraffin (of questionable quality and
>purity...buckets in a factory, after all), lanolin/whatever in the
>non-sulphuric-acid-treated bushing cloth, brass center pins (anyone
>ever done a substantive analysis on the content of these?), and then
>the environment (in which humidity and contaminents may very well
>play a part). Of all of these, I've been most interested in the
>paraffin/lanolin/brass interaction, as it seems that something might be there.
>
>On the other hand, as we've also noted, at this point, most of these
>actions have been the recipients of the tender minstrations of
>generations of technicians who simply didn't have some of the
>analytical tools and processes which we do now; and used whatever
>was at hand to "fix" these kinds of problems. Once anything else is
>introduced into the mix, then all bets are off. Fortunately, we do
>have a "real" fix in simply replacing the affected parts...time and
>budgets allowing. Folks with neither simply have to understand that
>things will never be "right".
>
>I do think it's odd that, while most older S&S actions are now
>affected to some degree or other, there are some which never seem to
>be so adversely affected. Earlier in the thread, someone mentioned
>seeing some that were still working well; and I've certainly seen
>any number of those, as have most folks on this list.
>
>Best.
>
>Horace
>
>
>>Regards,
>>Fred Sturm
>>University of New Mexico
>>fssturm at unm.edu
>>
>>
>>
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