Adhesives For Paleontological Conservation

The aim of this study is to describe the conservation and restoration procedures applied to the Pleistocene archaeological sites of Camino Cave, Navalmaíllo Rock Shelter and Buena Pinta Cave of Pinilla del Valle, Madrid (Spain). Clear-cut and timely decisions must be made when retrieving fossils and the close collaboration of a multidisciplinary team is the key to success. Early diagnosis is made in situ to determine the state of conservation and decay. A balance is sought between what the bones need, the available resources and the scientific data requirements of each site.

The principle of minimum intervention is followed throughout the entire process. Sub-fossils that were not successfully extracted were sent to the laboratory where a new diagnosis was performed. Previously collected on-site data provide helpful information for performing treatments that ensure the material's structural stability. The last step is careful packing of the bones pending further study.

In fossil preparation it is often necessary to bridge a gap or reconstruct an area to form a strong
support for a cantilevered or weak area of bone. This means that a material used as a fill must fulfill
certain requirements. It must be stable and non-flexible, and should not shrink or crack over time. It
must be strong enough to support the fossil, yet be readily removable if desired. It should also be
workable - so that the surface can be shaped easily. Texture presents other problems in a filler. Some
of these are purely esthetic objections, as in a filler that has a grain size that is too large for the scale
of the specimen. Qualities desired in fill materials change with scale changes - microscopic fills are
quite different from larger fills. Many materials that may be acceptable or even preferable for larger
bones may be undesirable at a small scale.
Through time preparators have used many products to perform this function, ranging from plaster to
epoxy putties. I have tried a number of materials, particularly on small fossils, which for differing
reasons have been unsatisfactory. One stable filler often recommended is Paraloid B-72 in
acetone or alcohol filled with microbeads or Cab-O-Sil. In practice, though, this can be difficult to
work with on a small scale, often undoing the very join one is trying to repair, by using a filler with
the same solvent as the adhesive. Additionally, filled Paraloid B-72 loses some of its properties as an
adhesive, remains somewhat flexible, and thus makes the fill weaker than the pure adhesive.
I resolved to make a series of samples to try to discover the filler of my dreams, using both differing
fill materials and differing solvents. I have described some of the qualities of fill materials, such as
adhesiveness, strength, hardness and workability, even though these qualities will always remain
objective. This paper will show the results of those comparisons, hopefully, leading to the discovery
of one or several fill materials that meet all of the above requirements.

Foaming is a general problem in the manufacturing of fatty polyamides. It is mainly affected by the mixing rate and reaction temperature. The effect of the reaction temperature and rate of mixing on foaming are investigated. Time minimization for the polyamidation reaction to prevent foaming is performed. The process constraints are the rate of temperature increase and the rate of the production of water. It is found that with an increase in the mixing rate, foaming starts at lower temperatures and with a decrease in the mixing rate, foaming only starts at high temperatures. For each mixing rate, with an increase in the temperature, the duration of foaming is shorter because the increase in the rate of foaming ends. Temperature profiles with time for different mixing rates are generated, and it is found that the reaction time decreases with increasing mixing rate. The generated temperature profiles are verified experimentally, and no foaming is observed. © 2005 Wiley Periodicals, Inc.

http://onlinelibrary.wiley.com/doi/10.1002/app.22714/full

ACRYLIC POLYMERS (RESINS) Methylmethacrylate (MMA), Acryloid (Paraloid) (Rohm & Haas) ethylmethacrylate (EMA), B72 (EMA/MMA)1 40 R medium; S: Ac, EtOH. A/C commonly used in conservation. ... Lucite (Perspex) (MMA) ~40 R medium; S: CCl4 A/C.

Stabilization of residual soils is studied by chemically using cement and rice husk ash. Investigation includes the evaluation of such properties of the soil as compaction, strength, and X-ray diffraction. Test results show that both cement and rice husk ash reduce the plasticity of soils. In term of compactability, addition of rice husk ash and cement decreases the maximum dry density and increases the optimum moisture content. From the viewpoint of plasticity, compaction and strength characteristics, and economy, addition of 6-8% cement and 10-15% rice husk ash is recommended as an optimum amount. © 2004 Elsevier Ltd. All rights reserved.

http://ac.els-cdn.com/S0950061804001734/1-s2.0-S0950061804001734-main.pdf?_tid=1864bf2a-66e4-11e3-b575-00000aacb35e&acdnat=1387261740_f0d281b7ab2e8395f6d7a56ac5b0bf42 
http://www.sciencedirect.com/science/article/pii/S0950061804001734

Foaming is a general problem in the manufacturing of fatty polyamides. It is mainly affected by the mixing rate and reaction temperature. The effect of the reaction temperature and rate of mixing on foaming are investigated. Time minimization for the polyamidation reaction to prevent foaming is performed. The process constraints are the rate of temperature increase and the rate of the production of water. It is found that with an increase in the mixing rate, foaming starts at lower temperatures and with a decrease in the mixing rate, foaming only starts at high temperatures. For each mixing rate, with an increase in the temperature, the duration of foaming is shorter because the increase in the rate of foaming ends. Temperature profiles with time for different mixing rates are generated, and it is found that the reaction time decreases with increasing mixing rate. The generated temperature profiles are verified experimentally, and no foaming is observed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1817–1822, 2006

Abstract Will the number you put on your specimen, its tag, box or other housing, be legible in one hundred years? Is it rub-proof, water-proof, fade-proof? Will a future worker be able to remove it if necessary? This poster will present a plan for assembling an archival marking ...