Qualifying preventive conservation at archaeological excavations –– Barnes, LeeAnn
Supervised by Dr. Joelle Wickens
This study was designed to explore some of the current relationships between the disciplines of conservation and archaeology. The primary goal was to identify activities that fall under the category of preventive care. In addition to a review of literature, investigations included a survey on archaeological conservation for both conservators and archaeologists and personal interviews with experienced archaeological conservators. Through these references, it was discovered that ambiguity exists over the term preventive care as it applies to archaeological conservation. A review of the following conservation activities with an expanded notion of preventive care is presented: planning, supplies and materials, on-site lifting of finds, packing, transportation, finds processing, safety, surveys, storage, monitoring, documentation, security, emergency planning, conservation awareness, training, education, and outreach. This review of conservation activities attempts to elucidate the places where conservation and preventive care can contribute within the complexities of the archaeological process. Ultimately, the manifestations of conservation activities at a field excavation are related to the perceptions of the role of conservation. A brief look at perceptions of the role of archaeological conservation is presented. It appears that the integration of conservation into archaeological excavations is a changing and multi-dimensional endeavor. It is concluded that the discipline would be well served by periodical reflexive review of this dynamic relationship. General trends in professional organizations and heritage management indicate that the profile of conservation is rising and awareness is greater than in the past. In response to shifts in global heritage management, new directions for preventive conservation include the preservation of sites and artifactsin situ.This study moves towards "qualifying conservation at archaeological excavations" by examining ways that conservation can be incorporated into excavations and by assigning meaning to the term "preventive conservation" in field archaeology.
Fall 2009
Conservation of materials and resources –– Daly, Rose
Supervised by Dr. Joelle Wickens
In the current economic crisis and with issues such as oil shortages becoming headline news as they did in the 1970's, art conservators and heritage building managers are looking for ways to save energy. In addition they are feeling the societal push to become more 'green'. This study investigates how the environmental parameters required by a collection can be met using sustainable practices. To save both energy and money it is possible to turn off Heating Ventilation and Air Conditioning (HVAC) systems. If the systems are turned off when the buildings are unoccupied it is more likely the conditions in the buildings will remain stable. By turning off HVAC systems for short periods of time, for example when the building is closed, the systems can be run in a more sustainable way. The project researched the practice of these short shut-downs, and included a three-day HVAC shut -down test at Winterthur. Winterthur is a historic house that has 175 period rooms with various materials including: furniture, decorative arts, works of art on paper, books, paintings on wood and canvas, leather, basketry, glass, metals, and textiles. The building has thick masonry walls, insulation, and double pane windows. The HVAC was installed in the 1960's. The parameters at Winterthur in the winter are: 68°F-72°F, Relative Humidity (RH) 40% +/- 5%; in the summer the parameters are: 72-75°F, RH 50% +/- 5%. These parameters are a conservative standard for the materials in this collection. A mild week in September was chosen for the shutdown, as the outside conditions would be similar to the collection parameters. During the 12-hour shutdown it was decided that if there were trends in the temperature and humidity moving quickly away from the parameters the systems would be turned back on. Monitoring was done in a thorough and systematic way, with readings taken by: building thermostats, thirteen dataloggers, and the building engineers took readings every two hours with a hand-held hygrothermograph. The shutdown was for 12-hours, the entire system was turned off from 6:00 PM until 6:00 AM, three nights were tested. The building temperature and RH remained within the parameters and the systems did not have to be turned on to regulate the environment. There were fluctuations, the overall trend was that temperatures were elevated a few degrees, and the RH was elevated a few percentages. The elevated temperature and RH is noticeable in the data charts, but when the data is examined in long time the changes during the shutdown are within the Winterthur environmental parameters. Interviews with conservators, archivists, and building managers gave insight into similar practices that will or have been taken at other institutions. These professionals described their experiences shutting down systems for days, or weeks, in a variety of climates spanning the United States. They spoke positively about their experiences, the environment in their collections remained stable or improved and they saved energy and funds, in some cases thousands of dollars were saved. Data was also collected about system setbacks, and the buffering ability of buildings with no environmental control. The success of these conservators and of the Winterthur test case may indicate to other museums the possibility of similar methods to save energy and funds while maintaining the environmental parameters required by their collection.
Fall 2009
The effectiveness of Avalure AC 315 as a sacrificial graffiti barrier for marble surfaces –– Roberts, Caroline
Supervised by Dr. Joelle Wickens and Richard Wolbers
Historic buildings, outdoor monuments and sculpture are especially prone to vandalism because of the public nature of their display. One of the more common forms of vandalism is graffiti. By definition graffiti represents any kind of graphic made on a surface, with aerosol spray paint being the most frequently encountered tagging medium. Tagging is a real problem from a preservation viewpoint, and Save Outdoor Sculpture, a Heritage Preservation initiative designed to engage the public in the protection of outdoor heritage, lists tagging as a condition criterion on both its Survey and Rapid Assessment forms (SOS website 2010). A real challenge faced by conservators and industries that specialize in the care of outdoor monuments is that the techniques of removing graffiti can be as damaging as the tagging itself. Methods include pressure-washing, abrasive cleaning, as well as overpainting, all of which can be harmful to deteriorated stone surfaces (Webster 1992). In addition, common practices in chemical washing, in which chlorinated hydrocarbons, glycols and various polar solvents have been used, pose health and safety concerns for the technician removing the graffiti (Graffiti Hurts website 2010). In response to the inherent difficulties of monitoring, protecting, and safely effacing the effects of vandalism from outdoor monuments, clear coating systems have been developed as a preventive measure against tagging. These systems are also referred to as graffiti barriers, or in cases where the coatings themselves are designed to be removed with the graffiti, as “sacrificial" graffiti barriers. Investigations into the benefits of sacrificial barrier coatings began in the 1960's and 70's as the occurrence of graffiti in major cities began to rise (Tarnowski 2007). The results of these studies are mixed. Natural and synthetic polymeric coatings in different solvents have been tested for their protective capabilities, but were found to result in changes in the stone's physical properties, including appearance and moisture permeability. These coatings were also shown to have varying degrees of reversibility (Ashurst 2002). There is a clear need for a protective coating that minimally changes the surface appearance and physical properties of stone, and that is easily reversible. Even if a coating meets these standards the question remains whether such a coating could be removed in a way that is less harmful to the person doing the cleaning, as well as the stone substrate. The main purpose of this study is to determine whether Avalure AC 315 meets the standards required in a sacrificial graffiti barrier, and to determine if aqueous cleaning methods can be used to remove it.
Fall 2009
A fungus among us: mold growth in museum environments –– Pack, Crista
Supervised by Dr. Joelle Wickens
Mold spores are everywhere. It may sound dramatic, but there is no escaping them and there is no way to prevent them from coming into contact with collections. However, there are methods for managing the environment in order to prevent growth from starting and thriving on collections items. A few Native American long weapons in the Alaska State Museum (ASM) closed storage cabinets were recently discovered to have an unusual fluffy white substance on their surfaces. This substance had the appearance and characteristics of mold. These objects were comprised of wood, bone, ivory, leather and feathers; and the white substance was found on each type of material. Mold was not initially a suspect on any of these objects, as the collections storage at ASM is kept close to the desired ranges of 50% RH (± 5%) and 70° F (± 3° F). Therefore, the finding of mold on ASM objects was perplexing, considering that the guidelines given to museums indicate that mold should not grow at the humidity conditions maintained by the ASM. The white substance appeared at some point while the objects were in ASM storage, as they were noted to be in good condition (without any kind of white substance on them) when they came into the collection six years ago. Additionally confusing was the fact that the weapons are stored with other items that do not show any white, fluffy growth. This raised questions as to why these items were being affected. First and foremost was to definitively identify the white substances on the ASM objects as mold and not a similar looking efflorescence or bloom. If confirmed to be mold, then what factors contributed to its growth? Essentially, the focus of this research was to determine if mold growth is dependent primarily on RH levels, or if other factors such as mold species, temperature, air flow, and substrate may contribute to its development. To answer this, a more thorough investigation of mold was conducted. This study of mold aims to answer questions regarding the physiology of mold, differences between mold species, and to determine if all species can be prevented with current guidelines for environmental control. The research was carried out through a literature review and experimental procedures. Literary resources were sought out that were directly aimed at collections care, as well as those that thoroughly explained the physiology and characteristics of fungi. Experiments pertaining to the identification of mold were carried out at the Winterthur and University of Delaware research labs in Wilmington and Newark, Delaware, respectively. The anticipation is that the answers to these questions may encourage people to reconsider their environmental parameters and recognize unique situations that may not fit within normal guidelines.
Fall 2011
Investigation into preferential insect damage of an 18th c. quilt –– Schuetz, Emily
Supervised by Dr. Joelle Wickens
Many collections worldwide contain objects composed of materials that are at risk from damage by pests; keratinacious objects in particular, such as woolen textiles, quillwork, tortoiseshell, and horn wares, are vulnerable to certain types of insects such as carpet beetles and clothes moths. There are a wide variety of factors which influence the locations of insect damage on a given object, including color: in a 2010 research project, Steven O'Banion documented the existence of preferential insect damage, finding a correlation between the color of parts of quillwork objects and their likelihood of their being damaged by pests. More literature research and scientific analysis of objects displaying preferential insect damage could provide more information about what makes certain parts of objects preferable to others. In turn, this information could influence the risk assessment of and guide the monitoring plans for vulnerable museum objects everywhere by suggesting where preferential insect damage is most likely to occur. In 2010, a wholecloth quilt in the Winterthur Museum's collection was discovered to be infested with case-making clothes moths and varied carpet beetles. Because the damage indicated a clear preference for a specific colored part of the object, it presented a good opportunity to investigate why the blue stripes were more attractive to the pests than the rest of the object. XRF and GC-MS analysis was performed on fiber samples taken from the quilt in order to identify the dyes and mordants present, and provide clues as to why the preferential damage occurred. The GC-MS analysis of the blue samples, the preferentially eaten areas, confirmed that the blue areas are dyed with indigo or woad, an unmordanted vat dye. The XRF analysis detected copper in the green yarn samples, the samples from the preferentially not-eaten parts of the quilt, which is significant. It indicates that copper was the mordant used for the yellow dye in the green thread and fabric. Copper is a well-known biocide, and its toxicity to many types of insects and marine life is becoming increasingly well documented. It was already known that the pests in question, case-making clothes moths and varied carpet beetles, prefer dark and undisturbed areas for feeding, and that they prefer greasier food to cleaner food, which contributed to the location of the damage on the underside of the quilt, as it was comparatively dark, undisturbed, and was more likely to contain residual soils from use. It now seems possible, however, that these pests particularly prefer indigo-dyed wool to other colors of wool because it is unmordanted, contains nitrogen, and because the alkaline vat dyeing process makes the wool fibers a little easier to eat. This knowledge can better inform collections care, and make integrated pest management more efficient. A schedule for monitoring based on dye-related risk could be developed to make the best use of staff time and resources.
Fall 2011
Independent study in preventive conservation: determining storage solutions for two 1950s-era aviator suits in the Hagley Museum collection –– Torok, Elena
Supervised by Dr. Joelle Wickens
In 1947, Chuck Yeager became the first pilot in history to fly faster than the speed of sound. This historic flight was enabled by a number of technological advancements in the previous decade that had allowed aircrafts to fly at much higher altitudes than ever before (Bilstein 2001). However, though flying at high altitudes allowed for higher speeds and faster travel, the physical and environmental forces on the human body at such heights are much greater than on the ground. Flight suits were concurrently developed that could distribute, circulate, and pressurize the human body to allow for the survivability of a pilot during high-altitude flight. Without these suits, high-altitude flight would never have been possible (Chatham and Clark 1959). One such flight suit was designed and manufactured for the United States military by David Clark Company, Inc. It was composed of a number of synthetic materials, a wide variety of which were developed and manufactured in the 1930s, 1940s, and 1950s. The incorporation of these materials enabled the execution of a design that non-synthetic materials of the previous century could have never been used to make, yet also created a system of considerable long-term conservation challenges. The Hagley Museum in Wilmington, DE has two of these flight suits in their collections, and both were manufactured in the early 1950s. Overall, each suit is composed of approximately twenty different materials, including fabrics, rubbers, hard plastics, metals, and foams. Almost all materials present appear to have been synthetically produced. Despite the fact that the suits appear to be in good condition, certain components are beginning to deteriorate in ways that compromise the objects both structurally and aesthetically. Many synthetic materials have proven to age in ways that are irreversible and deleterious to themselves and their surroundings. The inclusion of these materials in the overall composite system of both flight suits poses serious risks and tremendous challenges in their long-term preservation. Without proper care and maintenance, it can be expected that the condition of the suits will only worsen in time. Research has proven that the implementation of certain preventive measures can slow or arrest deterioration mechanisms of these materials overall, and these practices can prolong the life of these materials for years to come (Shashoua 2008, Quye and Williamson 1999). Understanding material composition is paramount in determining the most effective and appropriate conservation plans possible. This research study had two aims; first, to understand the composition of synthetic materials present in the suits and determine the deterioration mechanisms associated with them, and second, to use this information to propose a preventive conservation plan that can be used to ensure the long-term preservation of the objects. The implementation of the protocols outlined in this report will allow for the prolonged survivability of the flight suits; two objects that represent a significant era in military and aviation history.
Fall 2011
An environmental evaluation of Winterthur's China Trade Room as it pertains to the long-term care of its Asian lacquer collection –– Von Stein, Courtney
Co-supervised by Dr. Joelle Wickens and Dr. Stephanie Auffret
Asian lacquer (and the substrates to which it is applied) is extremely sensitive to fluctuations in relative humidity and temperature. In addition, lacquerware is incredibly light-sensitive; polymeric breakdown, cracking, and dulling of the surface are permanent and irreversible effects of light exposure. Therefore, long-term preservation of this material is largely dependent on environmental control. The research presented here focuses on an assessment of the environment in Winterthur's China Trade Room (CTR), a room on the third floor of the museum that is the permanent home for several of the museum's Asian lacquered objects. Relative humidity, temperature, and light data were collected via the use of two different data loggers. To supplement the logger data, an IR thermal imaging camera was used to evaluate the space and consultations were held with various museum professionals and Asian lacquer experts. High light levels and rapid fluctuations in relative humidity were identified as risks to the collection that is housed in CTR. Short-term and mid-term goals for the mitigation of these risks are presented. Data and recommendations presented in this report are meant to provide support for an IMLS grant application that seeks to provide interventive conservation treatment for several of Winterthur's Asian lacquered objects.
Fall 2012
Devising storage mount prototype(s) for the textiles of the DeBraak Collection –– Guidess, Gretchen
Supervised by Dr. Joelle Wickens and Bruno Pouliot
This project is a link, in a very long chain, of conservation study and analysis performed on a group of textile fragments that were found at a marine archeological site. TheDeBraakCollection came from the underwater wreck site of theDeBraak, a British ship that sank off the coast of Delaware in 1789. The entire collection numbers over 20,000 pieces and approximately 30% of the ship's hull. The textile portion of the collection consists of about 250 flat fragments and about six larger costume fragments that retain some three dimensionality. Textile specimens were brought to Winterthur/University of Delaware Program in Art Conservation in 2000 for the purpose of fiber analysis and documentation. A succession of students attempted to identify fibers and weave structure in an effort to connect the information with possible use on ship. (Szuhay, 2000; Peranteau and Larochette, 2003; McClosky, 2004; Ritschel and Sahmel, 2005). With the material investigated and the reports complete, it was recommended that the collection would benefit from preventive conservation planning. (Sahmel, 2005) During the Spring 2009 semester, as part of the requirements towards an additional concentration in preventive conservation, storage methods and techniques currently in use in both archeological and textile collections were investigated. This afforded an opportunity to examine storage housings employed in textile collections in the U.S. and Canada. In addition, a review of literature that dealt specifically with the storage of archeological textile fragments was undertaken. This augmented discussions with conservators and also broadened the study to include European methods and practices. This project culminated in development of a prototype for theDeBraaktextile fragments. Two examples and detailed instructions for making the passive storage mounts were produced. The prototypes were designed to work within existing storage cabinetry, and available space, while incorporating additional buffering material and increase protection, at the object level, against dust infiltration and light exposure. The final project report included instructions on how to implement rehousing using volunteer support, a source list for the materials needed, an estimate of material amounts, and minimum budget requirements to complete the rehousing project. Subsequently, the 250 flat fragments were rehoused by volunteers using the rehousing plan. Their work insures access for study, improves finding aids in this part of the collection, and minimizes the risks of damage. The project highlighted the challenges of preventive care for archeological textiles; maintaining what remains in as close to an unchanged state as when it was found. Talking with conservators, whose charge it is to care for this material, underscored the fact that even 'passive' acts such as storing material can have devastating and lasting effects on these objects, at times even worse than treatment intervention.
Spring 2009
An investigation into the color shift from purple to brown in a set of madder-dyed cylinder-printed furnishing fabrics from the Winterthur Museum –– Getts, Anne
Supervised by Dr. Joelle Wickens and Dr. Christina Cole
The focus of this semester-long project was to investigate the color-shift in a set of quilted furnishing fabrics from the collection of the Winterthur Museum. Dyed with madder and cylinder-printed on cotton, the furnishings under investigation include three sets of curtains, three valances, two bedspreads, and two bolsters (accession numbers 1957.1315.1a-2c and 1957.1316.1-6). Constructed in 1953 from historic 19th century fabric, the furnishings were displayed in the museum approximately six months of every year, for four decades. Presumably purple in color originally, the fabric has undergone varying degrees of discoloration. While some of the objects remain purple, others have shifted to brown. The discoloration can be separated into roughly into two categories – those that are brown but still retain a purple hue, and those that are brown and have an orange hue. It is hoped that by using this set of furnishing fabrics as a case study, information about the degradation pathway(s) will be obtained that can help prevent similar objects from suffering the same discoloration. Concurrent analysis is being carried out by Chris Cole, Mellon Foundation Fellow in Conservation Education, who is investigating the state of the dye at the molecular level. Analysis by liquid chromatography-mass spectroscopy (LC-MS) has indicated that no degradation products associated with alizarin or purpurin, the main colorants in madder, are present in the discolored areas. Since the colorant molecules are still intact, they are not responsible for the color change. Thus, there is an unknown factor, or factors, that is causing the textiles to discolor – and it is this unknown factor that is the focus of this investigation. The purpose of this project was to examine the problem from a 'macro' scale. The body of the report has been divided into a number of sections. Information was gathered to orient the reader to the history of the furnishings and their use, to describe the objects and assess their condition, and to examine the various pathways of degradation for cotton and madder. This will create a logical flow of information from which the preliminary hypotheses are drawn. It is hoped that from these hypotheses a series of experimental investigations into the cause of the color shift can be formulated. As well, general suggestions for the storage and care of these and similar objects are presented at the end of the paper. As the problem is better understood, these general recommendations can become more targeted in the pursuit to halt and/or prevent such color shifts. Located in the appendices are written and photographic documentation of the current condition of the furnishings. This information creates a baseline from which the condition of the curtains can be monitored for further changes. Thus, these images, along with the other information compiled here, can be of use in future investigations of these and similar color shifts.
Spring 2011
Stinks and stains: an evaluation of the threat posed to museum collections by Brown Marmorated Stink Bugs –– Moody, Ellen
Supervised by Dr. Joelle Wickens
This research project investigates the effects the brown marmorated stink bug (BMSB), orHalyomorpha halys, has on museum objects. A ubiquitous pest at Winterthur and other east coast museums, it is widely regarded as annoying, yet innocuous. However, BMSBs collected from an infestation at Winterthur last year were retained in a plastic bag and, after 24 hours, produced a brown-colored fluid. This raised alarm in Winterthur's Preventive Team, prompting this study, the main goal of which was to determine how these secretions might affect materials in museum collections. This was achieved by an experimental procedure of exposing fragments of representative collections materials to live BMSBs in a controlled environment, as well as consultation with texts and experts. Analysis of the BMSB secretion was also performed with Gas Chromatography Mass Spectroscopy and pH extraction tests. The experiment demonstrated that the secretion forms brown stains when deposited on collection objects. Analyses showed that the secretion contained acidic materials, fatty acids and bacteria – all compounds that may have a negative long-term impact on materials if left unattended. Thus, BMSBs can potentially cause both immediate aesthetic damage and continuing harm to collections materials, which makes preventing their exposure to these pests critical to affected institutions. How to manage BMSB populations in buildings and how to detect and treat materials stained with BMSB secretions was also addressed, though both these topics require further research. Since the BMSB was introduced to the United States in 1996, a multitude of entomological articles have been published on it and its impact on agriculture. To the author's knowledge, the BMSB has not yet received attention in the art conservation literature. This project indicates that understanding its effects on collections is urgent, as it has a greater potential to damage collections than conventionally thought. Specifically, studying its life cycle, determining the sort of damage it creates, as well as how to detect this damage, will allow conservation professionals to determine whether a BMSB-targeted IPM strategy is needed for their collection.
Spring 2011
Investigation into possible pest-attractive or deterrent qualities of dyes on Quills –– O'Banion, Steven
Supervised by Dr. Joelle Wickens and Dr. Christina Cole
It has been noted anecdotally that pests, such as Dermestid beetles, sometimes preferentially eat specific colors of quillwork and textiles made from proteinaceous fibers. These observations have led some to question if certain dyes either attract or deter pests. However, no formal survey has been previously conducted correlating pest damage to dye color. Color-specific pest damage is quite visually disruptive, as it often alters the overall readability of an object. Further, the removal of specific components can undermine an object's structural integrity. Knowing if specific dyes or classes of dyes attract or repel pests will benefit conservators and collections-care staff by allowing them to take preventative measures to protect their vulnerable items. This study investigated trends between dye color and pest damage on primarily pre-1856 Eastern Woodlands porcupine quillwork. Objects were examined in person and via images. In-person examinations were determined to be superior as they allowed for relative amounts of damage to be taken into account. Based on objects examined in person at the Penn Museum, white and blue quills were preferentially attacked by pests, while red and yellow quills exhibited less damage. Pests preferred to eat the quills that were blocked from light and/or soiled, indicating that factors other than the colorant must be considered. Based on objects examined via images, black quills were eaten less frequently than undyed white quills, while blue, red, and yellow quills were eaten more frequently. While the colorants used on some of these objects were known, no trends relating specific colorants to pest damage were observed. A collection of pipe stems from the Missouri River area suggested that trends noted for Eastern Woodlands quillwork may hold true for quillwork in other regions. Additional in-person examinations, combined with further scientific analysis of the colorants used on Eastern Woodlands quillwork, would help corroborate or contradict the trends observed in this study.
Spring 2011
Preventive concentration research project. 3D archival storage: practical guidelines for a small museum –– Promise, Ellen
Supervised by Dr. Joelle Wickens
This independent study satisfies one of the requirements of the Additional Concentration in Preventive Conservation offered by the Winterthur/University of Delaware Program in Art Conservation.The primary research goal is to synthesize available information to provide a useful set of guidelines for storing a small collection. Secondary research goals are to address what storage materials are appropriate or inappropriate for use in housing museum collections and what methodology has been employed to establish a material's suitability or lack thereof for use in housing museum objects. To answer these questions, a literature review and several site visits to local historic institutions have been undertaken. The guidelines produced by this study will be targeted to a rehousing project in the Winterthur Museum Archives. The archives, under the care of Archivist and Records Manager Heather Clewell, currently include approximately 600 three-dimensional objects in need of more appropriate storage housings. Some objects are resting on shelves out in the open, while others are resting on file cabinets. The collection is diverse and includes fragile materials, such as samples of human hair and pressed flowers, as well as more robust artifacts of metal or ceramic. Some objects present unique storage challenges because of their size or unusual shape. Examples include several saddles with straps and a set of golf clubs. Space is a limiting factor in considering options for new housings. Cost is also an important factor. Creative and efficient solutions are necessary.
Spring 2011
