In this presentation, Dr. Cordelia Rogerson spoke about radical changes in the approach to treatment decision-making at the British Library under her direction as Head of Conservation. The changes in approach were sparked by deep cuts to the Library’s budget, resulting in a reduction of the number conservators working in the lab by half–from 70 conservators to 35. At the same time, there was increased demand for conservation work in the busy library where collections are constantly in use. These cuts forced conservators to evaluate the fundamental nature and purpose of their work to determine if they could do less treatment without compromising use of the Library’s collection.
In response, the British Library conservation department adopted a “fit for purpose” model to govern how much treatment to do for materials sent to the conservation lab. Items are evaluated to determine what treatment is absolutely necessary for the immediate projected use of the item, and only this necessary treatment is undertaken. “Vulnerable damage” (such as a long tear across a page) is likely to be repaired, while “stable damage” (such as a loss at the corner of a leaf that does not interfere with safe handling) will be left untreated in many cases. This represented a shift away from a previous emphasis on full (or more complete) treatment for the majority of the materials coming to the lab. The new model does still allow for high priority items and items selected for exhibition to receive treatment beyond stabilization.
After applying “fit for purpose” to seven discrete projects with positive results, the model was adopted as the guiding principle for all work in the lab. By doing only the work deemed necessary, the lab has greatly increased the number of repairs completed each year. At the same time, the efficiencies gained have actually allowed the conservators to devote more treatment time to high priority collections.
As one of only two conservators working in a lab for a medium-sized special collections, I found that many of the challenges, decisions, and compromises of the changing operations at the British Library sound familiar. I appreciated hearing how a “fit for purpose” decision-making structure works in the setting of one of the largest institutions of its kind and the dramatic impact it can have in cost-savings and efficiencies on this scale.
In the future, I would be interested to hear more discussion of “fit for purpose” decision-making in the conservation of library and archival collections, digging deeper into the diverse interpretations that might emerge for a range of materials in varied contexts.
Tag: AIC’s 42nd Annual Meeting
42nd Annual Meeting, Workshop Session, May 28, 'Essentials of Inpainting' by James Bernstein.
The Essentials of Inpainting workshop was well attended and greeted by a very welcoming James Bernstein adorned in wonderful kilt regalia. The one day workshop was presented predominantly through power-point presentation with plenty of interaction and discussion with the participants. The main head table was packed with portable workstation blocks holding a huge array of color pigments. The workstations were made from Ethafoam® and were light-weight and versatile. Examples of fillers were also available to examine which emphasized the essence of choice and considerations when thinking about filling and inpainting surfaces.
The day focused on practical application rather than ethical considerations due to time limits and varying contexts that conservators work within. A great booklet full of useful handouts which echoed the content of the presentation was provided from the start which helped prevent excessive note taking and increased knowledge transfer throughout the day. The booklet provided a summary of the content of the workshop; materials, concepts and participants experiences which included preparation, techniques, varying reactions of the choice of media, brushes, study of pigments, paints and their properties, toning and patination and in-painting standards. Complementary material relating to the presentation was included which was thorough in content which really helps with later revision.
James reminded the delegates of the importance of establishing a sense of the character of the object and all layers beneath the paint film need to be evaluated as all these elements effect one another. When thinking about inpainting, wicking and capillary actions need to be controlled and identifying inherent and altered states needs to be deciphered. These were just many of the considerations taken into account when trying to approach inpainting on various surfaces. Good support during treatment application was considered essential to enable good control. Painting sticks, plexi blocks and rolls were other alternatives if working with other substrates. Having a well organized and labeled pigment selection was highly recommended along with strong light and magnification.
Fill material and techniques were discussed and the importance of isolating areas requiring infilling to reduce the risk of leeching of binders. James spent a lot of time explaining the varying techniques to apply fill material to enable good inpainting. I particularly enjoyed learning about the use of cellulose fibers as they were compatible with cellulose materials such as canvas, paper and other organic objects. The material is inert and is easy to remove. Solka-Floc® was used as an example of Microcellulose Purified Cellulose fibers available in varying fiber lengths which can be used with the adhesive/consolidant of your choice. Differing techniques regarding reversibility of inpainting was also discussed such as how the Getty Conservation Institute use tissue overlays as an isolating method and as a form of reversibility. Drying time and shrinkage of fill material was considered an issue; if the fill is not applied well they have a tendency to sink in the center due to the material drying from the outside in, leaving the center to dry last. Applying the fill as thickly as possible will aid in less shrinkage, which is another common challenge with fills. James explained the effects of fill materials on inpainting through a failed project he had completed some time ago which highlighted how an incorrect fill could be detrimental to the inpainting applied. This was a great lesson. James presented all kinds of techniques with regards to good lighting, burnishing and smoothing.
Color and pigments were reported which led to a reminder of the color theory and pigment indexing. It was rather rewarding as a textile conservator to learn James is more fearful of dyes than pigments which really emphasized the complexity of dyed textile substrates in comparison to the complexities of pigmented paint film. The potential for dyes to migrate and bleed is a very real one and control can be difficult. Refraction and transmission of light were covered, as were issues surrounding whites, inerts pigments and black pigments. These can be difficult pigments to manipulate and a comprehensive pigment and particle chart was supplied which included health concerns.
The session progressed onto binders and polymers and the effects of low and high molecular weights with regards penetration. James advised to always check the composition of pigments, just because pigments have been selected for conservation use, it does not mean it is safe. Building up color slowly is essential to help with replication.
When first I realized the amount of information which was being packed into this one day workshop I thought the day would be too overwhelming. I was pleasantly surprised as to how much I actually understood due to the steady and consistent pace James presented his expertise. The handbook was incredibly comprehensive and James is very approachable as an instructor, both not just essential to inpainting but to training and developing.
42nd Annual Meeting, Paintings & Wooden Artifacts Joint Session, May 31, "Long Term Hygromechanical Monitoring of Panel Paintings," by Paolo Dionisi Vici
As a conservation student entering my first year of graduate study this fall, I was at first intimidated by the topic at hand and the thought of relaying this information to the conservation community, potentially including research scientists, techs, and seasoned conservators who may have a jump-start on understanding these concepts, their implementation, and design execution. However, Paolo Dionisi Vici’s presentation not only made the material pertinent and compelling, but also accessible to a layman like myself. I only hope I can do justice to the complexities of the issue.
The talk abstract provides a great summary as to the ‘why’ of hygromechanical monitoring of panel paintings. Mathematical models and theoretical systems regarding the short and long term effects of environmental conditions on objects need to be substantiated by real life data sets in order to move forward with our understanding of the impact of microclimates (and their fluctuations) on objects. This topic is in direct diologue with the conference theme, Conscientious Conservation: Sustainable Choices in Collection Care, and harkens back to the opening session talks broadly titled Exploring Sustainable Preservation Environments, in which the generally accepted environmental paramaters of the museum were discussed, questioned, and even at times directly challenged. Data-logging by experimental measures, as exemplified by Vici’s talk, is paramount to the future of this conversation.
Vici posed an excellent question at the beginning of his talk by asking “What does stability really mean?” As an example of the potential complexity of this issue, he refered to the localized monitoring of one of the viking ships in Oslo, in which different data responses were logged based on the instrumentations’ location on the ship. The abstract aptly states, “Due to the specificity of each artwork… the analysis of an artifact’s response… can supply useful information about its “individual” sensitivity to the exhibition microclimate….” As the viking ship demonstrates, the complexity of individual responses can even vary within a single (albeit enormous in this case) object.
Now to get to the nitty gritty of the talk, and the part where I formally apologize for my unavoidable oversimplication (of what I suspect Vici already drastically simplified) of the sophisticated instrumentation used to monitor panel paintings. I should mention that while this instrumentation can be used to monitor a variety of wooden objects (such as the viking ship), the abstract notes that “panel paintings are useful in representing the complexity of possible reactions.”
The system of monitoring, the Deformometric Kit (DK), employs two displacement transducers, attached perpendicularly to the grain of the wooden panel. Linear deformations in the panel can be measured based on the proportional change of length of the transducers and subsequent trigonometric calculations. The transducers can be mounted on the back of a panel in different configurations and are not visible while the object is on exhibition.
The DK has undergone several design modifications to improve the specificity of the data being collected and its practicality in a museum context. In earlier models, the transducers were screwed directly into the panels. This complicated the data, because the specifics of what was being measured (surface vs. interior deformations and fluctations) could not be determined. Improvements at the Metroplitan Museum of Art were tested, and the transducers were eventually glued to the surface of the panel. According to Vici, minor shifts in the mounting glue would not negatively reflect the recorded data, because the information being gathered between the two vertical elements reflects general, averaged fluctuations. A further improvement was made when the base of the system was split, with ‘clips’ being glued to the surface of the panel and the transducers then being attached to these clips, making the transducers removable for transportation of the panel.
Vici provided several examples of the DK in action. Simulations of the potential asymmetry of a panel’s surfaces were conducted by connecting transducers to both sides of test panels. The effects of the movement of moisture as it reached equilibrium within the panel could then be monitored. The data Vici shared with us from these trials spanned hundreds of days, and the applicability of this system’s monitoring to both short and long term condition fluctuations should not go unmentioned. The DK also assisted in inform conservators regarding the appropriate crosspieces needed to provide auxiliary support for a long crack running through The Annunciation, oil on wood, Peter Candid, 1585. The DK was able to assist in determining how rigid the cross pieces needed to be and what kind of connection to the panel would be most appropriate.
I would like to reiterate that Vici did an incredible job engaging the audience with what could have been a very esoteric topic. And, yes, while it could be said that this is AIC, and perhaps only we could be ‘enthusiastic about dust’ (a group of people of which I am proud to be among), I felt the room earnestly abuzz after his talk. One of the most important thoughts that I took away from this talk was the importance of empirical validation of theoretical modeling. It is this sort of empirical validation that will inform our decisions as conservators and museum specialists moving forward with the care of our collections.
42nd Annual Meeting – Health and Safety Session, May 31, 2014, "Unintended Consequences of Persistant Residual Vapor-Phase Chemicals within Collection Storage" by Catharine Hawks and Kathyrn Makos
This talk, given in Saturday’s Health and Safety session, was a summary of a project at the Smithsonian’s National Museum of Natural History investigating the vapors that staff were exposed to when opening old storage cabinets.
Chemicals that accumulate from pest management or other treatments can be harmful to people, objects/specimens, and even storage furniture through inhalation, repeated exposure, and adsorbing or absorbing onto their surfaces. Many pesticides are particularly retained in lipids in specimens and in the wood components of storage cabinets – this has the potential to be problematic for those working with collections that were subjected to these types of treatments in the past, particularly natural history collections. The goals of the project were to detect, identify, and quantify concentrations of organic vapors in cabinets that were known to have held treated specimens, thereby being able to determine the level of risk. Entering into the project, mercury vapor was expected. Heavy metals and non-volatile particulates were not investigated, with the idea being that proper use of personal safety tools and regular cleaning with HEPA vacuums will negate their effect on humans.
Vapor data was collected via evacuated canisters using the USEPA TO-15 method, and a mercury vapor analyzer. Cabinets chosen for the survey were presumed to have not been opened recently (and some were known to have been left unopened for many years). Of the cabinets chosen, 55 held mammals, 100 held anthropological specimens, and 50 were empty but had held anthropological specimens in the past.
Results
Contrary to expectations, none of the cabinets were found to have mercury vapor! However, 39 other volatile compounds were found. Thankfully, these compounds were only detected in the ppb levels, and all volatile compounds detected were well below (often 100-1000 times below) workplace exposure limits (TLV).
Data obtained was not significantly different from the empty and the filled cabinets, which suggests that empty cabinets retain some chemicals, even after long periods of time. However, measurements of volatile compounds present in storage outside of the cabinets were not taken.
Though these ranges are safe for humans, they may not be safe for collections stored within the cabinets or for the cabinets themselves. Two chemicals are of particular concern: PDB (1,4-dichlorobenzene) and naphthalene are both highly toxic and will be retained in fats and other proteinaceous materials. They also increase mobility of unsaturated fats and are likely carcinogenic. In addition, PDB may crystallize onto surfaces, leaving a reside that can be quite sticky and difficult to remove.
Due to the results of the survey, the authors have a few key recommendations for collections that may contain such chemicals:
- Improve storage: Budget towards accelerated disposal of old cabinets. Do not reuse them, even with non-collection items. Re-house collections in metal cabinets, and segregate treated specimens from the rest of the collection.
- Implement an integrated pest management system: This reduces the need for future treatments and can be non-toxic! Heat treatment is not recommended for pesticide-treated specimens.
- Implement safe work practices and practice personal safetey measures: Wear gloves, minimize case-browsing, examine objects in a well-ventilated area.
- Work towards remediation: place scavengers in cabinets that can’t be evaluated or dealt with now.
- Above all, be aware and be safe!
42nd Annual Meeting – Paintings Session, May 29, 2014, "Oil Paintings on Metal Support: Study, Intervention, and Challenges" by Mónica Pérez
Mónica’s talk focused on the treatment of five oil paintings on meta at the National Center for Conservation and Restoration (Centro Nacional de Conservación y Restauración, or CNCR) in Santiago, Chile.
In 2012 five paintings from the Bernardo O’Higgins House Museum in Talca, Chile were brought to the CNCR in serious need of treatment. The paintings represented an exciting moment for the CNCR, since paintings on metal had not been treated there previously. One of the paintings was signed by Willem Van Herp, 1655, making it the oldest painting to be treated at the CNCR. All five of the paintings were bought in Europe in the 19th century by Eusebio Lillo (who also happens to have been the author of the Chilean national anthem) who donated his large collection of art to the museum upon his death in 1911.
Of the five paintings treated by the center, three were 21 x 29 inches, and two were much smaller, measuring 9 x 7 inches. Two had been previously cradled, and the rest were otherwise unrestrained. Four of the paintings were on copper, and one was painted on tin-plated iron. Various condition issues, all common with paintings on metal, were present; the most serious issues were corrosion (which consisted of brown stains and corrosion products protruding from the paint layer), distortion of the support, flaking paint, discolored varnish, and puncture holes where the paintings had been nailed to walls or altars. In addition, large areas of overpaint were present.
Treatment of the paintings began with documentation and an initial analysis of the imagery depicted. All of them appeared to be allegorical or religious, and a few were clearly similar in composition and subject to other, more famous paintings, such as the painting referred to as “Disciples of Emmaus” by the center, which featured two parrots that were exact matches to those in a Jan Breughel painting from c. 1620.
Cross sections of the paintings were taken in order to help conservators to distinguish between original and later paint. The four paintings on copper were found to have a lead white ground, and the painting on tin-plated iron had a ground consisting of Prussian blue and lead white. Varnishes were found to be mastic or dammar, but were clearly not original for several of the paintings. UV examination revealed aggressive cleaning and intervention in the past.
In order to determine the best methods for treatment, copper prototypes were created and used to test adhesion of various adhesives. The CNCR used Isabel Horovitz’s research into paintings on copper as the primary resource for their work. Following testing on the prototypes, corrosion was mechanically removed, and a solution of 15% B-72 in toluene was used to isolate the corroded areas and to consolidate flaking paint.
Distortions in the support were significant on a few of the paintings, and conservators hoped to be able to reduce it. Flattening was attempted on prototypes using a book press, and the result was considered to be less distracting. A few of the paintings were flattened in this manner. An acrylic plate was applied to the reverse to provide support and to allow the reverse of the metal plates to be seen.
15% B-72 in toluene was used as a base for filling losses in the paint surface, and a tacking iron was used to level the edges of the fills. Fills were isolated with a varnish and inpainted to a full visual reintegration. After cleaning and inpainting, the subjects of the paintings were revealed to be religious and not allegorical. The center has suggested re-naming the paintings accordingly, and has sent their proposed titles to the O’Higgins museum. The treatments and the revealed subjects will be summarized in an upcoming book.
42nd Annual Meeting- Book and Paper Session, May 29, 2014, "Preserving the African American Scrapbook Collection of Emory University Libraries by Ann Frellsen, Kim Norman, Brian Methot"
This three-year Save America’s Treasures project was presented in a three person tag-team. The project represented a collaboration between the Emory University Libraries Preservation Office, Digital Curation Center, and Manuscript, Archives, and Rare Book Library (MARBL). Emory University Libraries Conservator Ann Frellsen began the presentation with a project overview. The large scale of the project, combined with the diverse materials in the scrapbooks, required rigorous assessment and planning to fit the project schedule. The forty scrapbooks were narrowed to a group of 34 high-priority items. Then the scrapbooks were assigned to three treatment “levels,” roughly approximating the categories used in ARL (Association for Research Libraries) statistics, based on time and degree of difficulty. The past preservation approach for the collection had been to simply limit patron access by “boxing and forgetting.” For this collection of African American scrapbooks, the library intended to expand access through digitization.
The initial project proposal would have relied on a conservation technician, but the complex construction and fragile materials required a conservator’s skills. The project plan was adjusted, and the second presenter, Kim Norman, became the project conservator. The initial decision tree was quickly abandoned as the diverse scrapbooks were assigned unique treatment plans, corresponding to the specific preservation problems presented by each item. Common problems included folded items, detached components, and overlapping elements. Adhesive stains were generally left in place, where they provided useful evidence in positioning detached items.
In some instances, new support pages were created, but many of the album pages could be encapsulated or placed into unsealed Melinex sleeves to provide support at the page level.
The third presenter, Brian Methot, described the workflow for digitization. The reflectivity of the Melinex was a hindrance to photography, so the sequence of operations was adjusted to provide for encapsulation after digitization. Ehtafoam and binders’ board shims augmented cradles used during scanning. Custom-built platforms supported delicate fold-outs during photography. There was a vacuum table as a part of the photo studio, but the thickness of the materials made the vacuum ineffective. Instead, the photography used a sheet of Acrylite acrylic. Blank pages were also scanned to maintain the correct order and appearance of the pages.
Brian also described technical requirements for the project. The library needed a camera with a faster scanning back to capture details of these large and complex pages. Cool LED lights replaced hot tungsten studio lights as well. The Phase1 camera with Mamiya scanning back was tethered to a an Apple computer running Capture1 software, which handles both image processing and metadata. The process generated three file types: MOS native camera format files, Archival Master files (TIFF at 400 ppi with color target and ruler), and Production Master files (TIFF at 400 ppi, cropped to image).
The presenters further clarified the project details during the question and answer session. A major objective of the project was to make restricted items more accessible to the public. It is hoped that additional metadata can be crowdsourced through the open online repository with the digitized scrapbooks. There will be a digital-first access policy, so researchers will have to request special access to the originals. Regarding the conservation treatment, the paper was not deacidified prior to encapsulation. Pages were not necessarily sealed on all four edges, so this should not be a problem.
The project was successful in providing structural stabilization for the original copies, while also enhancing access to the scrapbooks’ contents. The project was discussed in Kim Norman’s blog and in the New York Times, increasing public awareness of the collection. The project has also begun to yield broader results by connecting community members with collection items.
42nd Annual Meeting – Collection Care Session , May 29 “Conservation Assessment at Schloss Leopoldskron in Salzburg, Austria: Promoting Sustainable Choices for the Adaptive Re-use of the Collection and the Site” presented by Rita Berg, Graduate Intern in Paintings Conservation, Brooklyn Museum and Crista Pack, Kress Fellow, Arizona State Museum.
Beautiful landscapes to boot, this talk illustrated how graduate students gained experience in preventive conservation by identifying the collections care needs of a prominent historic site that is also a busy event space/hotel.
In the summer of 2013, four students from New York University and the Winterthur/University of Delaware Program in Art Conservation — Rita Berg and Cybele Tom (NYU) and Crista Pack and Emily Schuetz Stryker (WUDPAC)—performed a conservation assessment of the historic collection at the Schloss Leopoldskron, under the supervision of Hannelore Roemich, Professor of Conservation Science at NYU and Joelle Wickens, Associate Conservator and Preventive Team Head at Winterthur. The talk was dedicated to Emily who passed away unexpectedly in February of this year.
Crista and Rita presented by discussing the building’s history, the goals of the project, the group’s workflow and theoretical approach, recommendations for the future, and lessons learned. The Rococo palace was commissioned by Count Leopold Anton Eleutherius von Firmian, and was once owned by Max Reinhardt. It is now an Austrian national historic site, and host of the Salzburg Global Seminar (SGS). The assessment project was co-sponsored by the Kress Foundation and SGS.
The Schloss is not only a magnificent edifice—it is familiar to many as the inspiration for the Von Trapp villa in The Sound of Music—but its historic collection includes paintings, works of art on paper, furniture, decorative arts and sculpture. Unfortunately the collection’s condition has never been systematically documented.
The major goals for the project included developing a long-term strategy for caring for the collection, as well as providing educational training for students who were able to test theoretical approaches in a “real-world” scenario (though it was admittedly hard to think of the bucolic, dream-like setting of this palace as “real-world”). However, major challenges quickly presented themselves to the students: food and beverages could be found throughout the house, candles were lit regularly, there were many open windows, objects vulnerable to theft, chaotic transportation and storage of objects during events, wildlife, dust and dirt accumulation.
The group worked in pairs to assess rooms, and three different types of object groups (prints, paintings and architectural elements) using photography and written survey forms that they had developed. They interviewed staff and local scholars, recorded patterns of use and consulted existing literature from the National Parks Service and the Conservation Assessment Program.
Among their recommendations were that the SGS articulate the presentation of the building and collection directly in its mission statement, appoint a collections manager, establish guidelines for events and handling. They also identified that the paintings, which were among the most valuable objects, are at the highest risk.
Although they found inherent contradictions in the house’s dual function as a historic site and event space/hotel, the students aimed to raise awareness among staff, owners and guests of the collection’s needs. This was done they maintained, keeping in mind the priority of the space’s functionality. This July a new team of conservation students will continue the project following the guidelines established by their predecessors. And judging from the Alpine landscape, lucky them.
42nd Annual Meeting – RATS Joint with Objects Session, May 30, “Technical Study and Conservation of the ‘Bat Wing Ship,’ Background, Challenges and Surprising Discoveries, Lauren Anne Horelick , Objects Conservator, Smithsonian National Air and Space Museum
The compelling object at the center of this paper is an experimental prototype of a Nazi German jet powered fighter aircraft discovered by the Allies at the end of World War II and brought to the United States for study. Designed by the Horten Brothers (Reimar and Walter), this craft with a steel structure, paper-thin plywood veneers, and no vertical tail is regarded as a design predecessor to the stealth bomber. The aircraft, a model Horten Ho 229 v3 (the third and final version of this particular airframe) was captured when it was near completion in the Gotha workshop http://airandspace.si.edu/collections/artifact.cfm?object=nasm_A19600324000 Charcoal was said to have been added to the construction adhesives to make the aircraft invisible to radar.
While always a favorite of air flight/military history buffs, this craft has never been exhibited and has been the subject of increased interest in recent years due to what the paper’s author describes as a “sensationalized” documentary entitiled “Hitler’s Stealth Fighter.” This video, available on YouTube, is replete with inaccuracies including the assertion that it is stored in a “secret government warehouse” when, in fact, its current home is the Smithsonian’s Paul E Garber Facility in Suitland, Maryland. However, it will soon be moved to another disclosed location – The Udvar-Hazy Center in Chantilly, Virginia where it will have its big reveal.
In preparation for this move, conservators at the Smithsonian NASM carried out a technical study to inform treatment protocol for the stabilization of the unstable and extensively delaminating veneers. They sought to characterize and identify the adhesives and other materials employed and, in particular, seek evidence for the presence (or apparent lack) of charcoal.
The aircraft is 55.4 feet wide with a tubular steel frame. The engine rests in the center of the craft and it is covered in a plywood skin. There is a clear canopy for the pilot. Due to complications of working on the object in its storage location, the decision was made to disassemble the damaged plywood portions to allow for treatment of the panels in the conservation lab. The composite materials that were examined and analyzed included the plywood board, structural supports and spacer blocks including the adhesives used to attach these portions to one another.
After a literature review of plywood available in Germany before WWII, reference materials were acquired for the potential materials. A sampling protocol was developed and the object and reference samples were examined under visual and Polarized Light Microscopy, FTIR, Raman, and for selected samples XRD was employed. (There may have been other methods employed that I missed in my notes– GC-MS and 3-D microscopy were mentioned in the abstract – sorry if I have omitted something significant.) The analysis was done in conjunction with the Museum Conservation Institute.
The analyses yielded some unexpected results as some of the wood sample results varied from those specified by the Horten Brothers (as reported in their interrogation). However the substitutions of European Beechwood/Scots Pine for the specified birch was not very surprising to the authors given the materials shortages at the end of WWII. The adhesives tested were identified as urea formaldehyde and phenol formaldehyde. Confirming the presence of charcoal in the black paint/adhesive layers proved elusive. The black particles were difficult to separate from the matrix. PLM examination did not support the charcoal identification and they were found to be amorphous with XRD. FTIR analysis pointed to the presence of cellulose, hemi cellulose and phenolics. This could mean oxidized or charred wood – or neither.
Plans for treatment do not include repainting damaged areas as the author mentioned a growing trend toward exhibition of aircraft in a less heavily restored state. Beech veneers will be employed in areas of loss but were unavailable in the United States in the <1mm thickness required so must be ordered from Germany. Because the urea formaldehyde has cross-linked with age and become insoluble, the conservators are not as concerned as they might have been about adding new materials when they choose an adhesive to stabilize the veneers.
Details and updates on this research project and the treatment are available on the on the National Air and Space Museum’s Airspace blog http://blog.nasm.si.edu/restoration/horten-h-ix-v3-bat-wing-ship-may-2014-update/ The Bat Wing Ship is poised to be a popular attraction when it goes on exhibit – I know my interest has been piqued by this interesting talk!
42nd Annual Meeting (Objects Session 5/31/14) – "Testing and implementation of microclimate storage containers for small metals and plastics" by Dana K. Senge
Dana’s talk – the last of the Objects session talks given at AIC’s 42nd Annual Conference in San Francisco – presented the results of multiple tests conducted by the National Park Service (NPS) Intermountain Region Museum Services Program, evaluating several readily available materials for their ability to protect sensitive objects from less-than-ideal climate conditions. Tests sought to identify the best methods for long-term storage of two distinctly different categories of collections materials: archaeological metals and historic plastics. The ideal solutions would be cost effective and easy-to-use, would allow for easy monitoring and access, and could be consistently applied across all NPS sites.
Archaeological Metals
Various storage systems for archaeological metals have been employed at NPS sites in the past, including Stewart boxes, 2-4 mil polyethylene (PE) bags with twist ties, and heat-sealed Marvelseal enclosures in combination with desiccants and/or scavengers.
Following the work done by JP Brown (2010) and Alice Paterakis (2011), Dana did some short experiments to confirm that resealable PE containers with silicone gaskets held a microclimate better than similar containers without gasketing. This being established, she added data loggers and twice the calculated amount of desiccant recommended for the container’s volume, and conducted a longer test in three locations – Arizona, where storage conditions were generally dry (about 35% RH); Montana, where conditions ranged from 25-45% RH; and Texas, where conditions fluctuated around 50% RH. Even under the most humid conditions in TX, the worst-performing silicone-gasketed PE boxes only allowed an increase of 2% RH over the course of the year-long test period. Measurement of the TX test box after a second year registered only another 2.7% increase in RH. Based on this set of experiments, Dana calculates that this particular setup would only require recharging with desiccant every 5 years if a change of less than 15% RH was desired. In addition, Oddy testing of the materials involved in the system confirmed that there was nothing harmful being off-gassed.
Historic Plastics
To find an ideal solution for historic plastics, Dana started by consulting Yvonne Shashoua’s 2008 publication, Conservation of Plastics. She learned that different polymers have wildly varying requirements for safe storage: cellulose nitrate (CN) and cellulose acetate (CA) need ventilated or scavenged environments to slow deterioration, while natural rubber fares better in anoxic environments, and polyvinyl chloride (PVC) calls for only non-absorbent glass or Mylar fabrication materials. The deep trays with Tyvek covers that had been in use at NPS since the 90s were not effective, so alternatives were sought.
For use with CN and CA, several box designs were evaluated for their ability to ventilate the space and prevent dust accumulation inside the box. Acid-free board boxes were made with slatted or screened walls and were tested without lids, with Hollytex lids, or with acid-free board lids. Inside the prototype boxes, Dana placed a deteriorating CA shower curtain ring along with a sticky surface to determine how much dust found its way in, and A-D Strips to monitor for the buildup of harmful acetic acid vapors. Findings supported the use of a blue-board lid, as it prevented the most dust over a month-long period. Though screened and slatted boxes did equally well, the screened boxes were found to be easier to construct. No harmful buildup was detected by the A-D strips in any of the boxes.
As a space-saving alternative to ventilated storage, Dana next evaluated several common scavengers in conjunction with the previously described resealable PE containers. In order of their performance (worst to best), they were Kodak Molecular Sieves, a single MicroChamber board, Getter Pak, two MicroChamber boards, and Zorflex. The most effective adsorbent, Zorflex, prevented acetic acid build-up in the container for 18 days. Interestingly, each scavenger tested lowered the humidity in the box to some extent initially, though it did eventually rebound. A second round of tests that doubled the amount of scavenger found no benefit to doing so. Future work will include evaluating activated carbon cloth, and rerunning the above described scavenger tests on boxes containing a larger amount of deteriorating CA to see if the products can keep up with increased volumes of off-gassed acetic acid. She would also like to test resealable glass containers in this capacity.
Although storage for PVC objects was not extensively discussed, Dana mentioned that she has been using and is pleased with heat-sealed 1 mil Mylar enclosures. She prefers the use of a single-impulse heat sealer to a double-impulse model to make the enclosures.
Finally, Dana made a point to address a few limitations of the systems she evaluated for this paper, including size (the largest silicone-gasketed PE containers she’s been able to find only measure 9 x 12 x 6 inches) and the need for a robust monitoring/maintenance plan.
Questions/comments after the talk:
- One talk attendee mentioned that she had found much larger gasketed PE boxes, but that they didn’t necessarily seal well because of the distance between the clamps, especially on the long edges. She recommended testing the container with water – if it’s not watertight, it won’t be airtight either!
- A question was posed about the efficacy of these systems compared to non-gasketed PE boxes that were sealed with aluminum tape instead. Dana stated that aluminum tape was not evaluated in this round of testing.
- Dana, though she didn’t mention brand names, cautioned that some brands of containers definitely held a better seal than others. Test your enclosures first!!!
I really enjoy hearing about research with practical applications. Thank you, Dana, for a well presented and interesting talk!!
42nd Annual Meeting – May 30th, "Sustainability Roundtable" hosted by the Sustainability Committee
What does it take to get your institution to do something about sustainability? The Sustainability Committee roundtable sought to create a space to discuss facilitating change at our institutions. In full disclosure, I am on the Sustainability Committee, however my role at the Annual Meeting did not include organizing the roundtable. Jia-Sun Tsang and Sarah Stauderman lead a discussion of five sustainable issues, focusing on the Smithsonian Institution (SI) as a case study. This was followed by a discussion amongst the audience, who were divided into groups of two.
The five sustainable issues were recycling, reuse, making a difference/activism, preservation environment, and lighting. After the presentation of these five, the audience was invited to add additional issues they would like to discuss, which included planet sustainability (especially water consumption, CO2 emissions, exotoxins emissions).
- Key factors for improving the success of recycling at the Smithsonian were improving communication between housekeeping and facilities and educating the staff about how to recycle.
- Reuse of materials occurs at an individual level, through units, and across museums. For example, the SI has a process for reusing equipment, exhibition cases, etc. that are no longer needed at a particular branch. A
- Activism was profiled through the experience of Eric Hollinger, an employee at the SI who has had a major impact on green issues. He sees himself as an “agitator,” “assistant,” “advisor,” and “advocate.”
- Making changes to the preservation environment occurs best when all the relevant constituents are at the table (facilities, conservation, curatorial, etc.). An example of effective change to preservation environments was a Smithsonian wide summit that occurred last year.
- Colonial Williamsburg recently worked across departments to make changes to their lighting system and switch to Light-Emitting Diodes (LEDs). Further information on that case study can be found on the Sustainability pages of the AIC wiki. Another case study for successful changes to lighting is the partnership between the Smithsonian American Art Museum and the Department of Energy.
Sarah Stauderman gave us a crash course in management theory to give us the tools and mindset necessary to create change. Learning to frame the conversation to effect change takes practice. These conversations work best if you have a defined purpose and engage multiple perspectives. Change happens most quickly when you can collaborate, compromise, and negotiate with your colleagues. Keeping things simple and aiming for small outcomes will help to get the momentum going on your project. When you do get a meeting, think carefully about where the meeting will be held and if you can make it an experience or in some way engage the constituents in the issue.
We then broke into pairs to discuss the following three questions. The goal of this section was to help participants practice the dialogue and thought processes that facilitate change.
1) What do you need to achieve the goal?
2) What in your organization is keeping you from your goal?
3) What training/resources do you need?
Personally, I found it helpful to have a framework to start thinking about change. Talking through ideas with my partner was encouraging and provided valuable insight. I hope that the other audience participants were able to take away a feeling of optimism about their ability to implement new sustainability initiatives at their institutions.