Waterlogged horn

We are dealing with a waterlogged horn comb from the 18th Century.
After impregnation in Polietilenglicol 400 we performed a slow
drying.  We observed a deformation and exfoliation in several layers
when arriving at 85% HR.  The material had lost its flexibility
also, so it was no possible to reach its original form again by
pressure without breaking it.

As a first measure, we have increased again the environmental
humidity to 100% and the horn it looks stable and a little more
malleable but still not enough to perform the reshape.

Has anybody any useful experience about that subject?  We are
thinking about using a hot spatula to reshaping it or re-immerse it
in a bath with temperature, but no idea of which it would be the
appropriate method and specific temperature.  We also think about
which adhesive/consolidant could be used to avoid a new shrinking
and deformation and to stick the different parts.

We would really appreciate any knowledge of previous experiences.

Irene Garcia Alonso
Archaeological Conservator


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                  Conservation DistList Instance 29:36
                Distributed: Saturday, February 6, 2016
                       Message Id: cdl-29-36-024
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