Archaeological Conservation Using Polymers

Over the years, archaeologists have developed a number of techniques for conserving historical artifacts for future generations. Along with these techniques, researchers have developed a series of ethical principles for treating materials in a way that allows them to be not only observed and analyzed for the present, but also in re-studied in the future. Conservation techniques used up to now, however, have provided artifacts only a limited lifespan, and in some cases they do not work well with water-logged materials. Within the past few years, archaeological chemistry and concerns of longevity testing have become central issues in the development of conservation treatment strategies. This problem became particularly acute when members of the Texas A&M Nautical Archaeology Program were called on to conserve artifacts from La Belle, the sunken ship of La Salle excavated in the 1990s off the coast of Texas by the Texas Historical Commission. Entombed in the mud that sealed it from decay for over three centuries, C. Wayne Smith writes in his introduction, the waterlogged hull and hundreds of thousands of fragile artifacts, including brain matter in the skull of one unfortunate sailor, would have been a futile conservation effort without new preservation technologies.Working with Dow Corning Corporation, Texas A&M's Archaeological Preservation Research Lab (APRL), and the Conservation Research Lab (CRL), Smith and his colleagues in A&M's Nautical Archaeology Program set out to develop a series of chemistries and techniques that would provide successful and affordable treatment strategies for organic materials. In this ground-breaking description of the processes and materials that were developed, Smith explains these techniques in ways that will allow museums and historical societies to conserve more stable artifacts for traveling exhibits and interactive displays and will allow researchers to conserve new discoveries without sacrificing important information. Beyond the advantages offered by polymer replacement (Passivation Polymer) technologies, Smith considers a concept seldom addressed in conservation: artistry. Variance in equipment, relative humidity, laboratory layout, intended results, and level of expertise all affect researchers' ability to obtain consistent and aesthetically correct samples and require a willingness to explore treatment parameters and combinations of polymers. Smith prescribes an effective layout for day-to-day conservation of small organic artifacts and then examines some of the mechanical techniques used to process various organic materials from marine and land sites. He concludes with an exploration of new tools and technologies that can help conservators devise more effective conservation strategies, including CT scans and Computer Aided Design images and stereolithography. All archaeologists, conservators, and museologists working with perishable artifacts will benefit from the careful explication of these new processes, and those wishing to incorporate some or all of them will find the step-by-step instructions for doing so.
About the Author: C. Wayne Smith is an assistant professor in the Nautical Archaeology Program, an Institute of Nautical Archaeology Fellow, and director of the Archaeological Preservation Research Laboratory (APRL) at Texas A&M University, where he had previously received his Ph.D. To date, he and his co-researchers have been awarded three patents for this work with polyethylene glycol and silicone oils.