Terracotta roundels

We are working on a terracotta roundel which is located in an
outdoor setting. It has evidence of salt and frost damage to the
head, and we are worried about ingress of moisture to some deep
cracks over the winter period, which could lead to further frost
damage and loss. We are looking for a material we could use for a
holding repair, to seal and strengthen the cracked areas until more
permanent repairs can be made.

So far, we have considered a traditional lime mortar, although we
are concerned that to use a lime mortar may introduce more salts to
the terracotta, which could cause more damage in the future. A
suggested alternative is Paraloid B-72 with microballoons, but I am
not sure if this is an appropriate material for an external
terracotta.

I would be grateful to hear of any past experiences with carrying
out repairs to external (salt-damaged) terracotta sculpture, and any
suggestions of appropriate materials.

Kathryn Hallett
Conservation Scientist
Conservation and Collections Care
Hampton Court Palace
Historic Royal Palaces
UK
+44 20 8781 9814
Fax: +44 20 8781 9799


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                  Conservation DistList Instance 18:21
                 Distributed: Tuesday, November 9, 2004
                       Message Id: cdl-18-21-005
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