A REPORT ON A MINI-SEMINAR ON ADHESIVES FOR FOSSIL PREPARATION (original) (raw)
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Collection Forum, 2016
The tensile strength of a select group of common fossil adhesives (50% w/w Paraloid B-72 in acetone, Paleobond PB100, and Devcon 2-Ton epoxy) was tested over a period of 9 months. Because the testing process is destructive, the tests needed to be standardized to draw valid conclusions, and because large sample sizes were desired for the most statistically accurate results, limestone adherends were used as a proxy for real fossil specimens. Paraloid B-72 in acetone at 50% w/w demonstrated long solvent retention and took several months to attain full strength. Although it was the statistically weakest of the three adhesives, it still required a significantly large force to be exerted (275.56 lbs/in2; 19.37 kg/cm2) in order for it to fail after only 3 days. If fossil specimens joined with Paraloid B-72 are provided with appropriate archival support, then the adhesive will slowly attain full strength. Devcon 2-Ton epoxy was stronger than the limestone adherends and created minor or major substrate failure in the majority of samples, indicating that its use be restricted only to specific situations, such as heavy specimens that cannot be supported externally. Paleobond PB100 samples failed on average between 535 and 636 lbs/in2 (37.6 and 44.7 kg/cm2) and generally demonstrated adhesive failure, with some minor substrate damage. Paraloid B-72 demonstrated substantial tensile strength in this study and has excellent long-term stability and reversibility. Therefore, Paraloid B-72 should be considered the default adhesive in the majority of fossil preparation practices.
This paper highlights a pedagogical approach for first-year conservation students from diverse backgrounds in a multidisciplinary context. It discusses the challenges of providing students with knowledge about the use of adhesives in a range of conservation applications. It is based on experiences in teaching using a modular programme at the University of Amsterdam (UvA) that offers a five-year programme in Conservation and Restoration of Cultural Heritage. Understanding the chemical and physical properties of polymeric materials used as adhesives in conservation, and the changes in these materials on ageing, is an essential prerequisite for choosing an appropriate material for a specific conservation application. In a teaching environment, it is important to learn through a combination of theory and practice and this approach is advocated as an effective teaching method. This paper describes how the principles of adhesion may be taught through simple, easy to replicate experiments that are designed to highlight differences in properties such as film formation, bond strength, handling and application. The approach aims to promote critical reflective evaluation and to provide conservation students with a framework of knowledge and experience to make choices appropriate to the demands of the task.
Oxford Research Encyclopedia of Anthropology, 2022
An adhesive is any substance that bonds different materials together. This broad definition includes materials used in everything from hafted stone tools to monumental architecture. In addition, the combination of bonding, plasticity, and insolubility meant that some adhesives were exploited for waterproofing and sealing of materials, as self-adhering inlays and putties, and as paints, varnishes, and inks. Adhesives have a history of at least 200,000 years. Throughout (pre)history and around the world, people used materials, including bitumen/asphalt, carbohydrate polymers such as starches and gums, natural rubbers, mortars, proteins (from casein, soy, blood, and animal connective tissue), insect and plant resins, and tars made from various barks and woods. Adhesives thus are very diverse and have widely varying properties: they can be tacky, pliable, elastic, brittle, water-resistant, fluid, viscous, clear, dark, and much more. They are a plastic avant la lettre. These properties c...
Understanding preservation and identification biases of ancient adhesives through experimentation
Archaeological and Anthropological Sciences, 2020
Adhesive production is one of the earliest forms of transformative technology, predating ceramics and metallurgy by over 150,000 years. The study of the adhesives used by Neandertals and early modern humans currently plays a significant role in debates about human technological and cognitive evolution. Depending on the type of adhesive used, different production sequences were required. These can vary in complexity and would have needed different knowledge, expertise, and resources to manufacture. However, our knowledge of this important technological development is severely hampered by poorly understood taphonomic processes, which affects the preservation and identification of adhesive materials and leads to a research bias. Here we present the results from a 3-year field preservation experiment. Flint flakes hafted and non-hafted with replica adhesives were left to weather naturally on and below the surface at two locations with different soils and climatic conditions. Differentia...
Assembling an Archival Marking Kit for Paleontological Specimens
vertpaleo.org
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 kit, adapted for fossils from a similar kit for anthropological objects. Having a well-designed kit saves time, and can help to improve and standardize marking practices. The proposed kit includes a variety of high quality materials, including India ink, acrylic paint, Acryloid/Paraloid B72 in a convenient nail-polish bottle and also in a tube, Japanese and archival papers, Bristol board, and various dispensers, brushes, pens etc. Possible additions to the kit (such as disposable pens) will be discussed. Even the best materials can fail if not used well! This poster illustrates marking failures and solutions for problematic fossil surfaces (dark, rough, friable, very small or fragile, etc.), and problematic materials such as coated surfaces and plastics. Also included are a discussion of permanence and removability, looking both at the materials included in the kit and others that could be used or have been used in the past.
The 1st workshop of the NECLIME working group on fossil wood
The 1 st workshop of the NECLIME working group on fossil wood Brno, June 5-8, 2013 Report (Dimitra Mantzouka, Torsten Utescher) The 1st Workshop of the NECLIME working group on fossil wood took place at the facilities of the Mendel University, Faculty of Forestry and Wood Technology in Brno at the Building P, Lecture room P220 , and – as it has been underlined from all the participants -this was the best choice for such a meeting since this Lecture room was fully equipped with microscopes for every one of the participants and also with a microscope connected to the projector which could show in real time what the presenter was seeing under the microscope. This microscope was used especially at the last 10 minutes of some of the presentations. The participants had also the opportunity to discuss about their findings, since they were able to see under the microscope the original slides of every one during the coffee-breaks and also after the lunch, a process of inestimable value. The ...