Consolidation of terracotta tiles

During the 1995 excavation season at the Archbishops Palace in
Trondheim, Norway, a tile floor from a medieval armory was lifted
from a wet site and brought to the lab for cleaning and
consolidation. Of the almost 400 tiles we are lucky to have problems
with just a few. These are glazed tiles that after cleaning were
showing signs of soluble salts crystallizing on the surface during
drying.

The tiles in question have gone through a desalination process and
we now want to consolidate them. All the tiles are broken and
laminating. We are looking for ways to stick and consolidate in one
go.

The tiles are still immersed in water and we are interested to find
a consolidant that can be absorbed into the clay body while the
tiles are still wet, then air dried.  Perhaps a vacuum impregnation.

If anyone can suggest treatments and/or literature we would be very
grateful.

Tanja Roskar
Museum of Natural History and Archaeology
Trondheim, Norway

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                  Conservation DistList Instance 9:44
                Distributed: Tuesday, November 21, 1995
                        Message Id: cdl-9-44-004
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