Calcium oxalate on easel paintings

Jerry Podany <jpodany [at] getty__edu> writes

>In answering Flavia de Souza's query about oxalate films (on
>paintings) Jonathan Kemp <j.kemp [at] vam__ac__uk> writes
>
>>With reference to Calcium oxalate, in the case of films on stone it
>>has been discussed extensively as both a natural and artificial
>>protective layer...
>
>Oxalic acid has also been used by restorers as a method of removing
>iron stains from stone (mostly white marble) and as a general
>cleaning solution and final polishing method. ...

Although this has gone way-off from Flavia's original posting, it's
worth mentioning here that surface treatments utilizing ammonium
oxalate in combination with lime washes to create thin (oxalate)
films are being evaluated to treat the "weakened skin" of the 1911
New York Public Library, a building of both fine grained marbles
from Vermont and Carrara, as well as coarser marbles from Georgia
and Tennessee.

An article will be forthcoming in the Journal of Architectural
Conservation (Donhead Publishers)

    <URL:http://www.donhead.com/
        journal_architectural_conservation/
        journal_of_architectural_conservation_past_issues.htm>

    **** Moderator's comments: The above URL has been wrapped for
    email. There should be no newline.

Jonathan


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