Removing sturgeon glue

I have received an enquiry from a restorer without access to the
list who tells me that he has been working most effectively with
sturgeon glue to treat flaking pigments on paintings. Recently he
attempted to consolidate some medium, this time on a paper
substrate. He thinks that he may not have prepared the sturgeon
properly since it dried to form a thick layer over the surface which
he has been unable to remove. Can anyone suggest a means of safely
removing this layer.

Mark G. Vine
Conservation Resources (UK) Ltd
England

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                  Conservation DistList Instance 10:83
                  Distributed: Tuesday, March 25, 1997
                       Message Id: cdl-10-83-011
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