Bone fills

Gali Beiner <galibeiner [at] hotmail__com> writes

>I am working with some very large archaeological bones (elephants,
>hippotami etc.) and part of the collection here features fills for
>bone, made out of a combination of wax with pine resin and gypsum.
>Does anyone know about other instances of fills made out of a
>mixture of these specific materials, and the way they aged with
>time? ...

I don't have any experience with filling materials of bones, but
this kind of putty was often used in the 18th and 19th century for
the conservation of antique marble sculptures. Recipes for similar
putties can be found as late as at the beginning of the 20th
century. Just from looking at historic recipes it seems that waxes
and essential or drying oils reduce the brittleness of the putty,
and waxes cause higher bonding strength. The amount of resin seems
to influence the stiffness. The amount of fill material as gypsum or
marble powder depends on the desired viscosity, color and texture.
These putties tend to become brittle and loose their bonding
strength by shrinking over time, as well as they tend to yellow and
darken, which are probably some of the reasons they are not widely
in use anymore.

Did you ever consider placing a light core material like a stiff
type of Styrofoam into your gap and cover this with your putty? This
would probably make it much cheaper and also lighter.

Sophie Haake
Graduate Intern
The Getty Conservation Institute
+310-440-6877
Fax: +310-440-7711

From: M. Susan Barger <sbarger [at] mnm__state__nm__us>
Subject: Salt on glass

In reference to the discussion on deteriorating cover glasses,
during the mid-80s, I wrote an extensive paper on the materials
characterization of such glasses on daguerreotypes. At that time, I
also did characterizations of the interior surfaces of cover glasses
on other works of art and some of these observations are in my
paper. There is also a very extensive list of related citations from
both the conservation literature and the materials science
literature. See:

    Barger, M. Susan, Deane K. Smith, W.B. White (1989).
    "Characterization of Corrosion Products on Old Protective Glass,
    Especially Daguerreotype Cover Glasses", Journal of Materials
    Science 24: 1343-1356.

M. Susan Barger, Ph.D.
Small Museum Development Services Consultant
Statewide Traveling Exhibitions Partnership Program
TREX, Museum of New Mexico
P.O. Box 2087
Santa Fe, NM 87504
505-476-5089
Fax: 505-476-5102


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                  Conservation DistList Instance 17:16
                 Distributed: Wednesday, July 30, 2003
                       Message Id: cdl-17-16-001
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