Carbopol

I am trying to use gels made of Carbopol (Ultrez10) for cleaning a
wall painting. However, I noticed that sometimes the gel tends to
become liquid after a few seconds from its application and is
readily absorbed  by the substrate.

The gels tested so far were prepared using aqueous solutions with a
pH ranging from 5 to 8, and all showed the same problem. After some
research, I found out that Carbopols are not stable in the presence
of  cations. Do you know whether this is really the case? Have any
of you  encountered such a problem when using Carbopol gels on wall
paintings?  Is there a way to overcome this problem?

Ritianne Psaila
Paintings Conservator


                                  ***
                  Conservation DistList Instance 20:21
                Distributed: Wednesday, October 18, 2006
                       Message Id: cdl-20-21-014
                                  ***