In keeping with the conference theme of Practical Philosophy, or Making Conservation Work, Ariel O’Connor, currently at the National Air and Space Museum and formerly at the Walters Art Museum in Baltimore, presented a talk where an imperfect treatment method proved to be the best option. A nineteenth century Persian water pipe, or nargile, made of gilded silver and elaborately decorated with gemstones, was heavily tarnished and needed to be cleaned in preparation for an upcoming exhibit. The water pipe was first analyzed with XRF to determine the treatment; XRF indicated silver with copper, gold, and lead, but no mercury, suggesting the object was gilded with some process other than mercury gilding.
Test cleanings were done with several standard methods for reducing tarnish mechanically: cosmetic sponges, Duraglit polish, precipitated calcium carbonate, Long Shine silver polishing cloth, and Mars Erasers. Acidified thiourea, a chemical method of reducing tarnish, was not initially considered because of research showing the problems of thiourea – leaching of copper, microetching, and long-term detrimental effect of thiourea residues. (See for example, a recent article by Contreras-Vargas et al, “Effects of the cleaning of silver with acified thiourea solutions” in Conference Proceedings of Metal 2013.) While the mechanical methods, especially the erasers and sponges, were easy to use, the final appearance of the polished surface in the test cleaning areas was not as golden as expected.
Analysis with XRF led to a frightening conclusion: even the gentlest mechanical methods, such as a cosmetic sponge, removed gold from the surface. And as the object was gilded with a method other than mercury gilding, the gold layer was already very thing. Analysis after a test cleaning with thiourea, however, did not show the same loss of gold. The decision to clean the object with thiourea was reluctantly made. Steps were taken to use thiourea as safely as possible: dwell time was minimized, the surface was immediately rinsed with deionized water, and the work was performed in the fume hood because of the generation of poisonous gases. O’Connor introduced a novel technique for applying and rinsing the thiourea. Strips of non-woven cotton Webril Handi-pads were placed on the object then wetted with thiourea applied by dropper; rinsing was also performed with the handi-pads. Cotton swabs were used as little as possible because of the possibility of abrasion of the surface.
The treatment raised the important question of when is it acceptable to use a method that has been shown to be damaging. O’Connor articulated why, on this occasion, chemical cleaning with thiourea was the lesser of two evils.I look forward to seeing more research on the topic of cleaning gilded silver as well as discussion of the ethics involved in this treatment.
During the OSG tips luncheon, Ellen Promise, currently of Historic New England and formerly of the Isabella Stewart Gardner Museum, presented new techniques for filling and inpainting lacquer. The techniques, developed in collaboration with Jessica Choloros and Holly Salmon, are readily applicable to many types of objects, not just lacquer.
Lacquer objects, especially those damaged by light, have very sensitive surfaces; therefore creating fills in situ can be dangerous. In the technique presented, Golden Acrylic Regular Gel Medium in matte was mixed with acrylic paint to a frosting-like consistency. The tinted mixture was then cast out onto silicone release mylar. After drying, the paint film remains flexible, has the bulk required for a fill, and resembles the sheen of aged lacquer. The paint film is trimmed to shape with a scalpel and then adhered in place with fish glue or B-72. While the fill isn’t invisible at the edges, it is harmonious with aged, cracked lacquer and remains reversible.
Promise also described her experiments with inpainting lacquer, specifically the fine gold lines often found on these objects. While acrylic paint is easy to use, the texture and shine is often not a good match. Promise tested several other options – metallic pens and markers, metallic paints, and mica powders dusted over sizes. She evaluated the materials for color, texture, gloss, and adhesion to an acrylic substrate. For the object in her case study, a Chinese export table in the collection of Historic New England, she had the best results with a Decocolor opaque paint marker. The marker was a good color match and had a high pigment load without bulk. The marker, which produced a fine line, could be used directly on the fill, or the ink could be dispensed into a palette, mixed with solvent, and brush applied.
Last year, several prominent conservators specializing in the care of archaeological objects as well as interested archaeologists formed the AIA Education and Training for Archaeological Conservation committee. The goal of the group, led by Dr. Alice Boccia Paterakis, Tom Roby, and Claudia Chemello, is to better integrate conservation and field archaeology. More information about the formation of the committee can be found in the March 2014 issue of AIC News.
Several members recently met at the AIA annual conference in New Orleans. Two working groups, each containing archaeologists and conservators who specialize in either land or underwater archaeology, were formed. The first working group focuses on the identification of required competencies for archaeological conservation and the development of education tools, whether site-based training or additions to university curricula, to meet these competencies. The second working group concentrates on outreach and dissemination, including research of relevant publications and journals and collaboration with allied groups.
For more information about this and other issues in archaeological conservation, please come to the ADG business meeting at 1 pm, on Friday, May 15, at AIC’s 43rd Annual Meeting. This post is promoted by the AIC’s Archaeological Discussion Group (ADG). For more information about ADG, please visit ADG’s webpage and visit ADG’s Facebook page.
Starting today, the American Alliance of Museums (AAM) is conducting an online survey on “direct care,” an issue of extreme relevance to conservators and one that could have a major impact on the future of the conservation field.
As most conservators are aware, deaccessioning museum objects is a complicated topic. Currently the AAM’s Code of Ethics says: “disposal of collections through sale, trade or research activities is solely for the advancement of the museum’s mission. Proceeds from the sale of nonliving collections are to be used consistent with the established standards of the museum’s discipline, but in no event shall they be used for anything other than acquisition or direct care of collections.”
While it is commonly understood that funds from deaccessioning should not be used for normal operating expenses, what does the term “direct care” mean? Does “direct care” mean conservation, and if so, could these funds be spent on conservation treatments? Or does “direct care” only mean preventive conservation? Either way, does “direct care” include conservation salaries? Because the term “direct care” is vague, the AAM has established the Direct Care Task Force to clarify the term and make new recommendations. Of course, each museum may have its own, more specific, guidelines and procedures. And while the AASLH also allows for money from the deaccessioning to be spent on “preservation,” the AAMD has stricter guidelines, allowing only for money to be spent on new acquisitions.
What does this have to do with conservation? If the definition of “direct care” were expanded to explicitly include conservation, more funding would potentially be available for conservation. But deaccessioning is already ethically challenging; conservators don’t want to be put in a position of seeming to encourage deaccessioning or to violate our own code of ethics, with our primary goal being the preservation of cultural property.
This important issue calls for dialogue – both among conservators and with our museum colleagues. AAM’s task force unfortunately does not include any conservators, so we must express our voice in other ways.
AAM Direct Care Task Force http://aam-us.org/resources/ethics-standards-and-best-practices/direct-care-task-force
It’s every museum’s nightmare: an errant spark from construction causes a fire; sprinklers unleash water on some of the most vulnerable objects in the collection. Luckily this museum had an emergency response plan. In the Dec. 26, 2014 Wall Street Journal article “After Fire, a Rush to Preserve History,” the conservators at the American Museum of Natural History (AMNH) faced this all too common nightmare and successfully and quickly responded. Ironically, the damage occurred in the Hall of Northwest Coast Indians, the recent focus of a multi-year conservation project, described previously on this blog and also presented at last year’s AIC annual conference. The conservation department, led by Judith Levinson (pictured in the article), quickly removed the affected objects, catalogued them, and performed triage. Levinson was also featured in a video by local news channel Pix 11. This occurrence raises the question: does your museum have a emergency response plan?
It’s summer (at least for a few more weeks) and for many of us, that means travel. Some conservators take travel one step further and fly around the world to do archaeological conservation at active excavations. Luckily for us back at home, many of them are blogging about their experiences. Here’s a roundup of several archaeological conservation blogs.
The Mugello Valley Archaeological Project/Poggio Colla has a long tradition of blog posts, going back to the late 90s – before they were even called “blogs.” Recent posts from conservator Allison Lewis can be found here. I love the use of RTI on incised bucchero sherds, as described by Poggio Colla intern and current UCLA grad student Heather White. Earlier posts from Poggio Colla can be found in the MVAP archives.
Turkey seems to be the center of archaeological conservation blogs – it must be all the strong coffee and tea! The conservators and interns at Gordion, where I was lucky enough to work one summer, blog about their time working at the ancient Phrygian capital here. This post really captures the feel of village life in central Anatolia. A great conservation-related post is this one about the on-going conservation of two Roman altars rescued from a nearby river.
Nearby in Turkey, the conservators at Kaman Kalehoyuk blog about their experiences at the Bronze Age and Iron Age site. This post makes nice use of a digital microscope in examining and sharing pictures of artifacts. Rounding out blogs about the Mediterranean world, the Kelsey Museum of Archaeology Dig Diaries are no longer being updated, but the archived posts still make for interesting reading.
The prize for the blog from the most exotic location, although certainly not the warmest, goes to the tough conservators of the Ross Sea Heritage Restoration Project in Antarctica, run by the Antarctica Heritage Trust. They are doing some amazing work, like the conservation of these newspaper fragments under challenging conditions.
Close to home and happily active again after a temporary closure because of funding, the conservators at U.S.S. Monitor Center are blogging about their work conserving the massive remains of the Civil War ironclad. This post gives one an appreciation for the complexity of working on such a large object.
That’s it for now. Stay tuned for a future post about museum blogs focused on archaeological conservation. If I missed a blog, feel free to let me know in the comments or via MemberFuse. And I’d love to see more blogs started, especially about archaeological conservation in other parts of the world such as Asia or South America.
This post was developed by the AIC’s Archaeological Discussion Group (ADG). For more information about ADG, please visit ADG’s Facebook page.
With her excellent talk, British conservator Pierrette Squires showed that it is possible to do a major collections move project while still being economically and environmentally conscientious. Of course, doing so required an enormous amount of careful planning, creativity, and hard work, which Squires outlined.
Situated in northwest England, an area hard hit by the recession, the Bolton Library and Museum Services (http://www.boltonmuseums.org.uk/) sold the textile mill which previously housed its collections storage. The staff then had to move and rehouse the collection of over 40,000 objects, ranging from fluid specimens to industrial machines, to a new location in two years and with a tight budget of $1.4 million. A large part of the success of the project resulted from the conservation team being included from almost the very beginning. Because of their involvement, the move was inspired by the green values of “Reduce, Reuse, and Recycle,” values which contributed not only to environmental sustainability but economic sustainability as well.
The location chosen for the new collections storage was another old factory. Despite some pollution and asbestos, the building was in good shape structurally. Working closely with the mechanical engineers, the museum did careful environmental monitoring of the space. The museum made the unorthodox decision not to install air conditioning, which would be expensive, but instead to use large amounts of insulation. Other green features of the building renovation included the installation of solar power panels and of Power Perfectors (voltage optimization devices), which save money by buffering energy draw. Adjustments like these resulted in a 50% reduction in energy costs.
Less expensive alternatives for outfitting the storage area were also sought out. Rather than using an expensive system designed for museums, cheaper compact storage intended for use in other industries was selected. Used metal racks and wooden pallets were chosen for storage of larger objects. In all, 65% of the storage furniture was second hand, saving money and keeping things out of landfills.
The arrangement of collections within the storage area was also carefully planned to maximize the environmental conditions of the building. For example, more stable objects like geological specimens were placed in areas against exterior walls, while textiles and archaeological materials were placed in areas farther away from the loading dock and thus most protected from temperature and humidity swings. Fluid preserved specimens were placed in the northern and thus cooler part of the building.
The actual move of the collection continued the theme of sustainability. Local transport companies were hired to do the actual moving, which saved on gas and contributed to the local economy. Storage and packing materials were reused as often as possible. When no longer usuable, materials were recycled.
In conclusion, the move was a very successful project. Although not all the choices made in the project are applicable to every museum – one wonders about the risk of pollutants from used and wooden storage furniture, the ideas presented in this talk were interesting and thought-provoking. The talk proved that environmental sustainability and economic sustainability are not opposites but can go hand in hand.
Foekje Boersma, along with Kathleen Dardes and James Druzik, provided an informative summary of the debate regarding environmental standards in their presentation “Precaution, proof, and pragmatism: 150 years of expert debate on the museum environment.” The presentation began with a historical review, based in part on information obtained from AIC’s Conservation Wiki.
The Museum of Fine Arts Boston and the Cleveland Museum of Art were the first museums to set specific humidity recommendations, in 1908 and 1915, respectively. It is often stated that the development of environmental standards arose as a by-product of the storage of artworks in salt and coal mines during World War II, so I was interested to learn of earlier attempts at environmental control.
In 1940, Harold Plenderleith and George Stout said there was not adequate information to fix an “absolute standard” but suggested 60 – 65% relative humidity, chosen because it was easiest to maintain with stability. Later, Plenderleith, now working with Paul Philippot, prescribed a “region of security” of 50 – 65% RH. According to Boersma, these early conservators were pragmatic: although a set temperature and RH were specified, a greater emphasis was made on avoiding extremes. The local climate and historical conditions of the objects were also to be taken into account. Garry Thomson, who is often assigned either the credit or blame, depending on whom you ask, for the 50% RH/70° F standard, is misinterpreted according to Boersma. He was also pragmatic. Rather than endorsing the 50/70 rule, he merely predicted the increasing number of museum loans would lead to museums adopting that rigid standard.
Boersma attributes the widespread implementation of the 50/70 rule to the museum building boom in the 1970s. Architects and engineers wanted numerical targets, and conservators were happy to specify safe conditions. Sustainability was not much of a concern given cheap energy costs. But already by 1979, CCI was advising seasonal variations with gradual fluctuations. Boersma then skipped ahead to the 1990s and the controversial research of Charles Tumosa and Marion Mecklenburg at MCI, which said that materials aren’t as sensitive as previously thought.
Today, the debate on the museum environment has moved from conservators to museum directors and administrators. The Bizot Group, concerned about environmental and economic sustainability, pushed to broaden environmental standards by adopting new Guiding Principles and Interim Guidelines, influenced by those developled by the NMDC (the National Museum Directors’ Council). In response, guidelines were published many other groups, such as AIC, BSI, AICCM, and the Doerner Institut.
In order to clarify the debate, Boersma divides prevailing views into three categories: precautionary safety, proven safety, and pragmatic risk management. Precautionary safety, embodied by the Doerner Institut’s Munich Position, centers around the belief that “stable is safe.” Not enough research has been done on the response of objects to wider environmental conditions. To eliminate risk, objects should be kept under a narrow set of conditions. Supporters of the proven safety approach acknowledge that actual conditions are wider than 50/70 because tight standards are impossible to maintain. The proofed fluctuations of 40 – 60% RH and 50 – 70˚ F are acceptable. Pragmatic risk management reflects ideas of risk assessment developed in the 1990s. Resources should go to the reduction of the biggest risks to collections, which may or may not be climatic fluctuation.
In conclusion, Boersma wonders how conservators can function as a profession given such different views on a central topic. She references her ongoing research as part of GCI’s Managing Collection Environments Initiative, which is working to answer questions generated by the debate.