Removal of soluble nylon from terracotta

Tony Sigel <asigel [at] fas__harvard__edu> inquires about the
removal of soluble nylon from unglazed terracotta.

It has been nearly 30 years since I last used this material, and it
was falling out of grace at that time but it was the only
consolidating material that when  applied its solvent wouldn't bleed
out the manuscript ink on the object I was trying to keep from
crumbling to dust and fibers.  The treatment was considered
irreversible, which was considered desirable by the client.  My
memory of this stuff is that it is prepared in hot ethanol and
applied while still warm.  I have never had an opportunity to try to
reverse it, but I guess I would try immersion in hot ethanol IF the
item or any related media can tolerate such procedure, or is small
enough to be handled in this manner.  I would think that anything
that might dissolve this stuff would only drive it further into the
terracotta.  My guess is that it is there to stay and that you might
be left with over-painting to mask its saturation.

Thomas M. Edmondson
Heugh-Edmondson Conservation Services, LLC
Kansas City, MO
816-283-0660


                                  ***
                  Conservation DistList Instance 21:13
                   Distributed: Friday, June 29, 2007
                       Message Id: cdl-21-13-007
                                  ***