Marble plaque

I'm a conservator at the Object Conservation Department at the
Israel Museum in Jerusalem and I would like to present some
questions regarding the cleaning and consolidation a broken marble
plaque (120 x 205 cm). The plaque is fragmented and in many parts
the marble has a "sugar" quality and is extremely weak. It is very
dirty and had gone through restoration in the past with plaster
fills and at least 2 kinds of adhesives.

I have several questions regarding the consolidation and cleaning of
this object:

    1.  I know Keim-Silex was used in the past to consolidate
        objects in such state of deterioration. While it works well
        it is hazardous and it is necessary to use a fume hood,
        organic filter masks and the object cannot  be touched for
        at least 2 weeks after treatment. I heard of another
        chemical, named RC 80, by Rhodia Siliconi, Italy which is
        used for consolidation of objects like the one in question.
        Has anyone used it and can tell me more about it and its
        pros and cons?

    2.  Cleaning by laser gun: I saw it in operation in another
        place in Israel and was wondering if it safe for only the
        operator to use safety glasses or should other people
        watching the process be wearing the safety glasses as well?
        Also, what exactly happens to the dirt which is vaporized? I
        was wondering if the vaporized molecules are safe to be
        bouncing around and not be "collected" somehow. Is it safe
        to breath this air?

Paolo Recanati


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                  Conservation DistList Instance 14:29
                 Distributed: Monday, November 20, 2000
                       Message Id: cdl-14-29-027
                                  ***