Consolidation of terracotta tiles

This is in response to Thanasis Velios' recommendation to use
Paraloid B-72 as an adhesive in toluol.

I would avoid toluol (toluene) for two reasons: 1) toxicity, and 2)
the fact that it takes 2-3 *months* for toluene to completely
volatilize from a thin acrylic film, and longer for a thick film.
Fragments joined with B-72 in toluene often come apart or move
unless they are tightly clamped. If a slower setting time is
required, add a small amount of ethanol (10-15%) to the acetone/B-72
adhesive.  This gives a slower setting time and is much less toxic.

Stephen Koob
Department of Conservation and Scientific Research
Freer Gallery of Art
Smithsonian Institution
Washington DC 20560
202-357-4880 x276

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                  Conservation DistList Instance 9:46
                 Distributed: Monday, December 4, 1995
                        Message Id: cdl-9-46-001
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