AIC's 53rd Annual Meeting

In the spring of 2024, a fire at the Archaeology Lab at James Madison's Montpelier caused significant damage to collection materials, many of which were housed in polythene bags that melted under the intense heat. These recently recovered collections were in the initial phases of processing. Much of the contextual information and inventory that archaeological research depends on was recorded solely on artifact labels and paper lists that were also affected by fire. This paper outlines the development of a preservation strategy to address the state of the collection. The conservation methods tested include a combination of mechanical, thermal, and chemical techniques.The focus of the tests is twofold: first, to develop an effective approach for removing the melted polythene from the archaeological materials without causing additional damage; and second, to recover as much of the original inventory and contextual information as possible from the charred and melted labels. In collaboration with local public safety offices and archaeological repositories, further research is taking place to assess how the choice of storage materials may impact artifact preservation and recovery in fire events.

Penn Museum archaeologists began organizing Heritage West, a community archaeology project in West Philadelphia, in 2019. The initiative doubled as an undergraduate course in 2023 involving Penn faculty, staff, and students, as well as members of the public who live and work or whose families lived and worked in the immediate vicinity. Throughout 2024, lab work and processing of the materials took place at the Penn Museum, near the excavation site. Heritage West as a whole is a significant outreach and engagement opportunity that highlights local archaeological resources, makes field and lab experience accessible, and explores research questions of interest to people in the neighborhood closest to the museum.  

Archaeologists implemented extensive preparatory work to direct their focus and goals, concentrating on the Black Bottom, a once thriving Black community in the area now called University City. It was destroyed in the 1960s under the guise of urban renewal. The archaeologists believed that oral histories collected early in the project and existing archives about the area could be enhanced by archaeology. Excavation pushed the historical narrative of the neighborhood further back in time than living memory, adding material weight to stories of people who lived there, uncovering artifacts inspiring further memories and revealing aspects of daily life rarely recorded through other historical methods.  

Site conservation is about balance: the excitement of discovery and slowly revealing surfaces to avoid destroying historical data; the amount of material uncovered and the need for storage; the budget and the best supplies; the desire for democratizing access to archaeological training and the fragility of the archaeological record. The team experienced tight timelines and navigated continuously changing circumstances between the short excavation season (10 days over one semester), the physical location of the site in public spaces (a community center’s active gravel parking lot and yard), and the variety of excavators (from novice students and community members to practiced archaeologists). This excavation was not an example of perfect site conservation, but it exposed community members, undergraduates, graduate students, and museum staff to the effectiveness of a historical archaeological team that includes a conservator. Students in the class and community volunteers were interested in the relationship between the fields and had good instincts for asking questions most pertinent to each specialty. They quickly brought the conservator materials for possible identification, drew attention to more fragile finds for options for lifting and storing, and learned how to expose relevant maker’s marks, decorative surfaces, and other important details of recovered artifacts.  

The future of the collection is going to be decided in close collaboration with members of the team of volunteers who helped plan and excavate. This group of community volunteers all have current or familial relationships to the neighborhood or work in community organizations supporting current residents. It is hoped the artifacts will survive to be used in local artist efforts towards memorializing the neighborhood or on display in exhibitions, and that will be due to the efforts of the team to incorporate conservation considerations throughout the project.

In preparation for the Colonial Williamsburg Foundation’s new Colin G. and Nancy N. Campbell Archaeology Center (CAC) scheduled opening in 2026, conservation was undertaken on a variety of objects selected for display in the new exhibition spaces. As the fellows hired to begin this process, part of our work was the treatment of two carboy bottles. The glass bottles, one clear and one green, were first assembled in the 1980s following excavation from the historic site of the Public Hospital. By the 2020s, the bottles’ original use is unclear, the old adhesives were visibly degrading, and no treatment records could be located. Additionally, after decades in open storage in the Archaeology Collections Building, the soon-to-be predecessor of the CAC, the bottles were obscured by surface dust. Over eight months, we examined, documented, disassembled, cleaned, and reassembled the two bottles, becoming familiar with a variety of adhesive reversal methodologies in the process.

There are 138 clear and 187 green fragments, creating the project’s first challenge. The sheer number of fragments required a mapping system to denote their locations on the bottles. We created a panorama map for each bottle, on which every fragment received a unique name and a physical label to identify it throughout treatment. We also devised a spreadsheet to track the treatment progress of each fragment. At about two feet tall, these bottles required close teamwork, clear communication, and comprehensive organization.

Another challenge of this project was the unknown adhesives from previous mending. These generously applied, yellowed adhesives were not only visually distracting but also posed risks to the bottles’ structural stability. FTIR analyses revealed Duco rubber cement and Epotek 301 on the clear bottle, and epoxies – most likely Fynebond and Epotek 301 – on the green bottle.

We undertook treatment on the clear bottle first, and one of its adhesives proved extremely tenacious. To find an effective treatment method for what was likely epoxy, reversal testing was performed to find ZipStrip (methylene chloride) alternatives. First, hot water and 1:1 acetone and ethanol baths were tried, but both were unsuccessful. Next, four solvent bath combinations were tested with 49 xylenes:45 acetone:6 ethanol proving to be the most effective, which reversed many joins and minimized the use of ZipStrip.

Surprisingly, the green bottle proved much easier to disassemble despite the FTIR results conclusively showing epoxies. Most joins were successfully reversed with 1:1 acetone and ethanol vapor chambers and baths. The few tenacious joins were reversed with 49 xylenes:45 acetone:6 ethanol baths. Testing from the clear bottle treatment provided an effective solvent combination to tackle the stubborn joins, significantly saving time during the second treatment.

The scale and complexity of the project required creativity, collaboration, and eventually tacit understanding between the two of us. Organization was key, with the panorama map and spreadsheet preventing disassociation and ensuring smooth coordination. Reversal testing revealed safer methods for removing epoxies. After much time and dedication, the two bottles are revitalized and ready for display in the new CAC building.

Large archaeological objects can be challenging to manipulate during and after treatment due to a variety of factors including structural integrity/fragility, scale, awkward shape, and weight.  These characteristics often occur in combination making it difficult to determine where to make direct-contact to an artifact’s surface as well as to identify center-of-gravity and how it will shift as an object is lifted or rotated. Consideration too must be given to minimizing stress to weak points and ensuring that an artifact is adequately secured, so that as it is moved/turned, it cannot physically shift in an uncontrolled/unexpected manner. Due to the need to reach all sides of an artifact during treatment, it is usually unavoidable that it will have to be turned at some point which increases the risk of damage. Ultimately, once an object is conserved, it will have to be placed on a mount and moved into storage or put on exhibition which also has the potential to cause damage. As no two archaeological objects are identical, often what works directly for one object may not for another. However, overarching concepts can apply to numerous objects such as the utilization of multipurpose mounts that can be used over the course of an artifact’s treatment. These kinds of mounts minimize the need for physical handling and therefore reduce the risk of accidental damage. This paper will present a series of case studies utilizing primarily USS Monitor artifacts to highlight a range of techniques and methods employed at The Mariners’ Museum and Park to lift, turn, and store large archaeological objects over the course of the last decade.

From May 2019 through December 2024, 201 ancient objects from the island of Cyprus were examined, documented, and treated in preparation for permanent installation in The John and Mable Ringling Museum of Art. From 2020 onward, this conservation effort was led by Conservator of Sculpture and Decorative Arts Emily Brown, collaborating with guest curator and Cypriot specialist Joanna Smith and private conservator Dimitra Pantoulia. Along with her own treatments, Emily delegated and managed the majority of this treatment, which was completed by four other conservators working in close collaboration: The Ringling Kress Conservation Fellow Tara Johnston, Objects Conservator Dimitra Pantoulia, and RLA Conservation conservators Elena Bowen and Krista Vaughn. After a brief introduction to the collection and conservation history of The Ringling’s ancient collection, this presentation will focus on an overview of the collaborative treatment methodology applied to the 201 objects prepared for permanent display. Material types included limestone, ceramics and terracotta, bronze and precious metals, glass, and gemstones. The talk will include case studies for several treated objects and conclude with a brief post-mortem reflection on the treatment approach, including both successes and lessons learned.

This paper will highlight conservation activities that are part of Paisajes Arqueológicos de Pañamarca (Archaeological Landscapes of Pañamarca), a multidisciplinary and multiyear archaeological research project in northern Peru’s Nepeña Valley. Pañamarca was one of the most important monumental Moche centers during the Late Moche period (ca. 600-800 CE). The adobe site is best known for its polychrome wall paintings that depict mythological iconography and human ritual activity. Conservation of the immovable elements of the site, especially the wall paintings, has been a priority since excavations by members of the current team began in 2010. The project expanded in scope and capacity before the 2023 season with funding from the Avenir Conservation Center of the Denver Museum of Nature & Science. This expansion included the addition of more conservation staff and an enhanced focus on objects conservation and materials analysis. The excellent preservation environment at the site means that small finds are plentiful and span a range of materials, from sections of woven plant material to copper alloys. These small finds help to provide a more holistic sense of the archaeological spaces and the wall paintings that embellish the surrounding surfaces. This paper will provide an overview of how objects conservation has developed over two field seasons since 2023 at the site. To date, objects conservation has included both preventive and interventive activities; the paper will highlight examples of both, as well as some of the unique opportunities and challenges the project provides. Materials characterization has emerged as another area of focus for the project. Characterizing the paint palette for the site’s wall paintings exposed during excavation began with in situ analysis with portable X-ray fluorescence (XRF) spectrometry. Further analysis with polarized light microscopy (PLM) and Fourier transform infrared spectroscopy (FTIR) has started on samples removed and exported from the site. Objects conservation and materials characterization will help to situate the materials and methods of production encountered at Pañamarca within the broader Moche world.

Thousands of visitors to Valley Forge National Historical Park in Eastern Pennsylvania have passed by “the forge” while walking the Park’s many trails. The forge was constructed in 1742 to finish crude iron “pigs” into hardware and tools. However, in 1777, British forces burned the valley and the forge—a major strategic site—to the ground. The Pennsylvania State Park Service excavated the Upper Forge Site ruins in 1929-1930 before the Park’s transition to federal ownership. Until recently, over three hundred wooden fragments of the forge’s structure sat in a barn. The artifacts fluoresced bright green under UV and reeked of mothballs—a telltale sign of the petrochemical creosote. The condition of the collection lent itself to a major collaborative research project including the Valley Forge National Park and Harpers Ferry Center in West Virginia.

Before treatment began, we established a triage lab in an open barn to temporarily store the collection. This process required the cooperation of Valley Forge’s maintenance staff and Harpers Ferry Center in order to provide the necessary infrastructure and resources. Our greatest priority was to remove the creosote coating, thus allowing the collection to be relocated to a climate controlled environment. Creosote is composed of strong volatile organic carbons (VOCs), which can cause respiratory irritation and damage. Unfortunately, creosote removal scholarship provided little help in devising a treatment plan for the Upper Forge Site. While creosote can be removed on an industrial level using abrasives or water pressure, these methods were not suited to fragile archeological material. The treatment plan had to be designed and tested from the ground up.

The condition of the collection was suitable for comprehensive testing. Boxes of dissociated debris were available for spot-testing. The wood’s internal cell walls and structure had long since been destroyed by the outside environment. Fluctuations in temperature and humidity caused the objects to expand, contract, and severely split in the barn. Conservators do not typically recommend submersion baths for archaeological wood for fear of bursting cell walls with fluid. However, the Park was more comfortable with pursuing wet treatment because the collection had already undergone this damage during storage.

After I conducted analytical testing at the Harpers Ferry Lab, I employed triage-style processing at the Park. I treated the wooden artifacts using a combination of solution, mechanical, and poultice cleaning. The creosote removal also yielded new residue-limiting poulticing techniques. I encountered challenges during the numbering process, which required the insight of conservators across multiple states. The project concluded with a modular storage method, also designed by a committee.

The Upper Forge Site project was an experiment in collaboration. Craftsmen, curators, preservationists, conservators, and analytical scientists across the federal government provided their expertise to the protection of this historically significant collection. Within a year, we had relocated the forge fragments from a barn to a climate controlled archive. Historical research has been compiled for the eventually interpretation, exhibiting, and possibly even reconstruction of the revolutionary forge.