PVA emulsion

Gillian Comerford <gmpc [at] nhm__ac__uk> writes

>Could anyone recommend a PVA emulsion with a neutral pH and good
>penetration (small particle size). I propose to use it on sub-fossil
>bone.

PVA emulsions, by their very nature, are acidic.  I recommend using
the acrylic colloidal dispersion Acrysol WS-24 (distributed as
Primal WS-24 in the UK).  This should be easily available from Rohm
and Haas (UK) or one of their distributors.  It has a pH of 7, and a
glass transition temperature of 40 C, which is much better than the
PVAs.  I recommend 2-4% to start with; re-application as necessary.

See
    AIC 1981 Preprints
    "Consolidation with acrylic colloidal dispersions" and

    IIC Adhesives and Consolidants, (1984)
    "The consolidation of archaeological bone"

Stephen Koob
Department of Conservation and Scientific Research
Freer Gallery of Art
Smithsonian Institution
Washington DC 20560
202-357-4880 x276

                                  ***
                  Conservation DistList Instance 9:40
                 Distributed: Monday, November 6, 1995
                        Message Id: cdl-9-40-002
                                  ***