Objects Conservation – Page 7 – AIC Blog Archives: Conservators Converse

Reminder: Registration is now open for Aluminum: History, Technology and Conservation!

Conference and workshop: April 7-11, 2014 in Washington DC.

Conference: April 7-9, 2014, Smithsonian American Art Museum, Washington, DC. To register: www.conservation-us.org/aluminum
Workshop: April 10-11, 2014, Emil Buehler Conservation Laboratory at the National Air and Space Museum, Steven F. Udvar-Hazy Center, Chantilly, Virginia. To register: www.conservation-us.org/aluminum-workshop
The conference will bring together international specialists to facilitate the exchange and dissemination of knowledge, experiences, and expertise in the deterioration and conservation of aluminum alloys. The workshop will focus on the identification of aluminum alloys and finishes as a professional development opportunity for conservation professionals.
The conference and workshop have a compelling line-up of featured speakers, and we are pleased to announce the keynote speakers.
Lyndsie Selwyn will deliver the opening address on the history, fabrication and use of aluminum. Lyndsie is Senior Conservation Scientist at the Canadian Conservation Institute in Ottawa, Canada.
Ian MacLeod will present on the corrosion and deterioration of aluminum and clarify different alloys and their corrosion problems in diverse environments. Ian is the Executive Director of Fremantle Museum and Maritime Heritage at the Western Australian Museum in Australia.
François Mirambet will present on materials characterization and identification of aluminum alloys and their corrosion products. François is a Research Engineer for the Centre de Recherche et de Restauration des Musées de France in Paris, France.
Christian Degrigny will present on the conservation of archaeological aluminum, including the stabilization of marine aluminum, as well as terrestrial and industrial artifacts. Christian is Senior Conservation Scientist and Lecturer at the Haute Ecole Arc de Conservation-restauration in Neuchâtel, Switzerland.
Rosa Lowinger will present on the conservation and use of aluminum alloys in contemporary art, with a particular emphasis on sculpture. Rosa is Principal and Senior Conservator of Rosa Lowinger and Associates in Florida, U.S.A.
Richard Pieper will present on aluminum in architecture, with an emphasis on the challenges of this material for the architectural conservator. Richard is the Director of Preservation at Jan Hird Pokorny Associates in New York City, U.S.A.
Bruce Hinton will present on corrosion inhibition, surface treatments and coating systems, particularly the latest developments in corrosion mitigation through development of innovative and environmentally friendly inhibitors and modern coating systems. Bruce is Adjunct Professor of Corrosion Science at Monash University in Victoria, Australia.
David Hallam will present on preventive conservation and the maintenance of aluminum artifacts and collections. David is Coordinator for the ICOM-CC Metal Working Group and a metallic heritage consultant in Tasmania, Australia.
For further information, email aluminum2014@gmail.com
You can download this announcement here
Organizing Committee: Claudia Chemello, Malcolm Collum, Paul Mardikian, Joe Sembrat, Lisa Young.

Archaeological Conservation at ASOR 2013

Three weeks ago LeeAnn Barnes Gordon and I co-chaired a conservation session at the annual meeting of the American Schools of Oriental Research (ASOR) in Baltimore, MD. Friends, I loved every minute of it.
This year the session, titled “Conservation and Site Preservation in the Near East,” kicked off at 8:20 in the morning on the very first day of the conference. We were concerned about the early start time, but attendance was good and the audience was engaged and responsive. This was the second in series of 4 planned sessions, and I’ll tell you about our lofty goals for the series a bit later. First, here are the 6 papers from this year, with a few notes from me about each:
“Preserving Egypt’s Cultural Heritage: Experiences Gained and Lessons Learnt”
Michael Jones (Antiquities Conservation Project, American Research Center in Egypt)

I was surprised to learn in this talk that ARCE’s fantastically comprehensive conservation and education programs in Egypt, underwritten by USAID, all began as a simple salvage response to the deadly 1992 earthquake. Michael spoke about building stakeholder support for conservation in Egypt, about the challenges of recent political turmoil, and showed us the wonderful results of conservation efforts at the Red Monastery in Sohag, among other sites. If you don’t know much about ARCE and its conservation programs, read more here.

“Training for the Conservation and Management of In Situ Mosaics: The MOSAIKON Initiative”
Leslie Friedman (Getty Conservation Institute), Jeanne Marie Teutonico (GCI), Kathleen Dardes (GCI), Thomas Roby (GCI), and Zaki Aslan (ICCROM)

Everything you’ve ever wanted to know about mosaics preservation, MOSAIKON is improving and teaching it. How to do a great job with locally available materials? They’re on it. Training for the next generation in-country? That, too. Conservation education in Arabic? Yes! Mentoring for conservators in the Middle East? Of course. What about my favorite site preservation solution, reburial? They’re studying the most effective ways to do it for mosaics. And of course, they are producing publications about it all. Check it out here.

“Digging on the Edge: Archaeology and Conservation at Kourion, Cyprus”
William Weir (University of Cincinnati), paper delivered by Stephen Humphreys

This site-specific case-study delivered great information and dramatic visuals of mosaics perched precariously on cliff-edge. It detailed, from the archaeologists’ perspective, the experience of working with conservators to document and save mosaics at a site. It also illustrated the complexities of conservation at archaeological sites; within a single site, the response to each mosaic differed depending on the mosaic’s location, construction, and the project’s ongoing research. A great talk illustrating successful collaboration in archaeological conservation and research.

“Painted Roman and Byzantine Cypriot Tombs: Properties, Processes and Preservation”
Ioanna Kakoulli (University of California, Los Angeles), Christian Fischer (UCLA), and Demetrios Michaelides (University of Cyprus)

This was an excellent talk for anyone interested in conservation of wall-paintings; these Cypriot rock-cut tombs have undergone structural damage from shifting bedrock and water damage from floods and rainfall. Ioanna also discussed the technical analysis of plaster, pigments, and binders for the paintings. This talk was also great for anyone interested in preservation and management of active tourism and pilgrimage sites: littering, vandalism, education and interpretation! How about making your conservation plan work for nearby hotels as well as an active monastery? Done. This talk detailed a comprehensive approach to a complex series of problems.

“Dilemmas in Preservation of Iron Age Sites in the Valley of Beer-sheba”
Zeev Herzog (Tel Aviv University)

Zeev’s talk beautifully, and humorously, detailed the decades-long effort to preserve mud-brick architecture at the site of Beer-sheba in Israel. An unusually inventive series of campaigns beginning in the 1960’s tried almost everything the determined teams could think of: chemical consolidation, firing the bricks in-situ with a portable kiln, capping the walls with new mudbricks, and, finally, capping and restoration with modern, fired bricks. In addition to illustrating a half-century of conservation and site preservation at a single site, this talk explored preservation and interpretation goals for important Iron Age sites in Israel.

“The Conservation and Technical Analysis of Ancient Near Eastern Objects at the Johns Hopkins Archaeological Museum”
Sanchita Balachandran (Johns Hopkins University)

As a conservator in a university archaeological museum, I’m always impressed by the JHU Archaeological Museum’s (and Sanchita’s) commitment to linking conservation to undergraduate teaching and using object-based projects to improve learning for students. This talk was especially useful because it had detailed case-studies of specific objects and projects. I especially liked the way Sanchita used these projects to develop transferable skills like observation and critical thinking for her students.

Back to our lofty goals – LeeAnn and I began this series of sessions with the goal of fostering collaboration and better integrating continuing education in the allied disciplines of conservation and archaeology. We want to bring more conservation information to our archaeology colleagues, and we hope to promote archaeology meetings as a forum for conservators. So far each session has been an excellent educational opportunity for us, and we hope our audiences have felt the same way. We’re grateful to our speakers in both years thus far and to ASOR for embracing the series.
Archaeological conservators, we hope you’ll join us for future meetings in San Diego (2014) and Atlanta (2015). If you’re willing to contribute to conservation sessions at either meeting, please write us! We’d love to hear from you. The deadline to submit abstracts for 2014 is February 15.
Suzanne Davis: davissl@umich.edu
LeeAnn Barnes Gordon: leeannbarnes@gmail.com

Two Mellon Postgraduate Fellowships: Paintings and Objects Conservation

The Brooklyn Museum is offering two Andrew W. Mellon Postgraduate Fellowships, one in paintings and one in objects conservation. Each position will be two years with the option of a third, each commencing in September 2014. The Fellow will carry out examinations, research, and treatments, produce and maintain technical documentation, and participate in preservation activities within the Museum. The applicant should be a graduate of a recognized conservation training program.

Each Fellowship includes an annual stipend of $34,000.00, full benefits including health insurance, and $2,500.00 in travel funds. Applications should be sent electronically as pdf files containing: statement of interest, résumé, and three examination and treatment reports with photographic documentation. These documents should be sent to Ken.Moser [at] Brooklynmuseum.org. Please include in subject line: “Andrew W. Mellon Fellowships Conservation.” Confidential supporting letters from three conservation professionals familiar with the applicant’s work should be sent directly to: Ken Moser, Chief Conservation and Vice Director for Collection, 200 Eastern Parkway, Brooklyn, NY 11238, or at e-mail above.

All application materials must be received by January 1, 2014. Receipt of application will be confirmed by e-mail.

AIC's 41st Annual Meeting, Wooden Artifacts Session, May 31st, “We Can Fix It, But Should We? Take 2: Contemporary Art Comes Knocking” By Tad Fallon

In addition to Rose Cull’s presentation on contacting the contemporary artist, or not, is a single case study by Tad Fallon. The object in question is a “Kosode” form cabinet titled “Meet Mr. Chips” by the California furniture maker, John Cederquist. I encourage everyone to check the website for images of other Kosode cabinets.
The cabinet is one of a series made of mixed woods, aniline dyes and epoxy resin and was completed in 2006. The owner had purchased it directly from a gallery exhibition. Displayed in a bright and sunny room in Connecticut, the highly decorated façade of the cabinet had faded dramatically, and the owner contacted Fallon and Wilkinson to have them treat it. The owner did not want to send it back to the artist for restoration.
Tad began the project with background research and then contacted John Cederquist directly. John was interested and friendly, and the conversation led to a visit by Tad to the artist’s studio. During the visit, Tad was given an in-depth tour by the artists assistant Chris Labont, and was able to take extensive notes and photographs of the artists materials, techniques and tools, enough to completely recreate the work from scratch.
However, the take-away was more complicated then that.
-From a conservators point of view, the materials and techniques were inherently problematic and prone to light damage.
-The large Kosode series techniques evolved over time and the techniques used at the end of the series were somewhat different from those used at the start.
-The range of materials available to the artist had changed over time, due to California VOC compliance.
-From the artist’s point of view, he had moved on, this was old work, and he was looking forward rather than back.
So what’s a conservator to do? The original work has faded and no longer resembles the original appearance or intent of the artist. The color and appearance cannot be “brought back” through intervention. The options are largely limited to:

Leaving it alone.
Creating a complete overlay from original materials on a reversible ground. (only marginally feasible)
Restoring the façade completely using the artist original materials and techniques as recorded directly from the artist and artist’s assistant.
Recreating the façade completely using improved materials that remain true to the original intent and appearance of the artist.

Not easy choices, not one of them. What would you do? I for one truly hope that Tad will be able to present “Take 3” next year!

AIC's 41st Annual Meeting, Wooden Artifacts Session, May 31st “ Contemporary Sculpture; To Contact the Artist or Not” by Rose Cull

I had really been looking forward to this presentation, especially as there were two WAG session presentations on the same topic, and Rose did not disappoint.
Rose began her presentation with some solid background information and began by defining contemporary art as being created by living artists, meaning I believe that the artist and viewer (and in this case the conservator) are both living at the time the art is being viewed. She also reminded the audience that the creation of art has changed from a means of expression based on a solid craft background to a means of expression where issues of stability or longevity may be of little or no concern. As the inherent instability of much contemporary art requires intervention to maintain some degree of the artist’s original intent over time, this lead to a short overview of the Visual Artist Rights Act (VARA) of 1990. The Act grants the moral right of artists to protect their works from derogatory treatment that may be prejudicial to the artist’s honor, reputation, or economic interests. (apologies for a very compressed overview of the Act which may be viewed in it’s entirety on the web). Rose made a point of noting that under VARA an artist cannot claim conservation as a “destruction, distortion, or mutilation of their work unless it is performed with gross negligence”.
Through her past experience in interviewing various museum related stakeholders she made one other important point. A work of art represents a specific point in an artist’s development or career. Although one may communicate with a contemporary artist and ask those questions that seem most vital to know about a specific work, the artist may have moved on, changed his or her working methods and lost or forgotten the inspiration for a past project. An artist may not view a completed work from their past with the same interest or perception as when the work was fresh, and in fact might create the same work quite differently today.
With the background information clearly presented, Rose offered two case studies, one with a sculpture by Louise Nevelson, and one by Cornelia Parker.
With the Louise Nevelson sculpture, Rose read Nevelson’s autobiography, researched her materials, looked at other works, and contacted the Nevelson Foundation. The Foundation is run by Maria Nevelson, Louise’s granddaughter, and Maria contacted Rose directly, offering enthusiasm and support by sending along a list of conservators known to have treated other Nevelson works. Armed with knowledge, support, and the consultation of fellow conservators Rose was able to address the issues and complete the treatment to everyone’s satisfaction.
The Cornelia Parker treatment was a bit more complicated, beginning with the fact that it was created from charred wood collected from a church that had been struck by lightening and burned. In this case she did not contact the artist. Although the reasons for treatment were rather mundane, an accumulation of airborne dust was beginning to distract from the presentation, the questions and answers might have lead to complications (I am paraphrasing here). In the end Rose created a system of careful and effective non-contact “dusting” effectively minimizing intervention.
Perhaps the most disappointing part of the presentation was the limited time left for questions, with only enough time to register the opposing views from the audience that 1. artists and Foundations were often impossible to work with, and 2. times have changed and artists and Foundations are much more receptive. Wish that could have been batted about for another hour!

AIC's 41st Annual Meeting-Workshop, May 29, "Plastics Last Longer if Treated with Intelligent Conservation", by Yvonne Shashoua and Thea van Oosten

I have a fascination with plastics, I guess it’s partly because the array of materials that can be chemically engineered seems to have infinite possibilities. Objects of many textures, shapes, colors and applications exist because of plastics. Unfortunately, their existence creates challenges to both preservation and sustainability. As works of art or material culture, conservators want to make them last for as long as possible, but the most long-lived plastics also pose the problem of disposal. The types of plastics that are most likely to break down in the environment are also crumbling to bits on the shelves of collectors and institutions.
This year’s AIC meeting featured a workshop presented by Yvonne Shashoua and Thea van Oosten, two well-known experts in the field of plastics in museums. Shashoua’s book, Conservation of Plastics: Materials Science, Degradation and Preservation, is a good reference. Both Shashoua and van Oosten were part of the 2008 European POPART initiative, (Preservation of Plastic Artifacts in museum collections), which selected a few types of plastics used in artwork, studied their deterioration pathways, and possible methods for their preservation, cleaning and repair. http://www.bartlett.ucl.ac.uk/graduate/csh/research/projects/popart
To begin the workshop, we were presented with a historic overview of many types of plastic materials encountered in collections. From gutta percha to polyester we learned of the properties and uses of different polymers. Van Oosten had an entertaining way of categorizing plastic types by their properties into three snack food groups; gummy worm, chocolate bar, or cookie. Gummy worm plastics are in the elastomer category, which includes both natural and polyurethane rubber. These materials are stretchy and flexible at room temperature. Chocolate plastics are the thermoplastic category, which includes polyethylene. These materials polymerize through addition and can be melted and reformed into new shapes. Cookie plastics are in the thermosetting category, which includes Bakelite (phenol formaldehyde), melamine formaldehyde and Vulcanite. These plastics are formed by condensation reaction with water being lost, and they cannot be reformed into new shapes with heat.
We learned that it is important to know what type of plastic you have before you attempt any repairs, because an adhesive that might work with one polymer will dissolve another. To help determine the appropriate adhesive, one should consult the Hansen or Hildebrand solubility parameter for the given plastic. The strength of bond needed, the viscosity of the adhesive and the elasticity of the plastic are other factors to consider. For lightweight polyurethane foam, water based adhesives commonly used in conservation are often adequate. Clear plastics, like polystyrene or polyester may require consideration of the refractive index of the adhesive in order to make an invisible joint.
In the afternoon we split into two groups. We had time to experiment with adhering and mending a variety of plastics, and test cleaning cloths, pads and swabs for cleaning plastics. According to results obtained from the POPART study, it is important to clean plastics as soon as possible when they become soiled, since particles may migrate into the plastics and become impossible to remove in a few short weeks. At the same time a soft cleaning cloth must be used that won’t cause abrasion to the plastic being cleaned. My experiences in this workshop highlighted the importance of testing on mock-ups!
The four plastics at greatest risk of deterioration are cellulose nitrate, cellulose acetate, plasticized (flexible) polyvinyl chloride, rubbers, and foams. Cold storage is typically recommended for these materials. The leaders of this workshop also recommended use of an oxygen scavenger in encapsulated packaging for preservation of rubber. Rubber in collections is rapidly deteriorating by oxidation, which causes it to turn yellow and brittle.
Along with POPART a number of research projects have brought the needs of plastics collections into the spotlight in recent years; however, it is clear that more research on active conservation methods is necessary. There is so much more to learn about fascinating plastics!

AIC's 41st Annual Meeting – Objects Session, May 30, “Bon Appétit? Plastics in Julia Child’s Kitchen” by Mary Coughlin

I wonder what Julia would think about the current state of her kitchenware? In Mary Coughlin’s talk, “Bon Appétit? Plastics in Julia Child’s Kitchen,” Mary discussed issues she and her Museum Studies class faced while inside the Julia Child Kitchen exhibition at the Smithsonian’s National Museum of American History (NMAH). Mary is an objects conservator and professor at George Washington University. Her class carried out a condition survey of the exhibition as it transitioned from its original installation into part of the new FOOD: Transforming the American Table, 1950-2000 exhibition.
The kitchen was originally located in Julia Child’s Cambridge, Massachusetts home from 1961 to 2001 and was the setting of her last three television shows. When Julia donated it to NMAH, the museum accessioned over 1,200 objects, ranging from spatulas to a Rubik’s Cube. The kitchen was installed in the museum as Bon Appétit! Julia Child’s Kitchen, a temporary exhibition that was probably only meant to be on display for less than one year. But as is often the case with well-loved exhibitions, it ended up being on display for a decade.
Mary’s class worked within the exhibition, actually in Julia’s kitchen on view to the public, as they carried out the condition survey. It seems as though many of the museum visitors also wished to step inside the kitchen, as Mary humorously noted that they often heard the thud of visitors walking into the glass partitions. In an effort to provide outreach to the public, a curator was posted outside the kitchen to discuss the project with visitors. In addition, the students wrote blog posts about their experiences which can be viewed on the NMAH’s blog “O Say Can You See?” (For example, see one student’s post here).
After the condition survey, the class made recommendations for ways to incorporate preventive conservation into the new exhibition. Two of the main problems encountered in the old exhibition were dust and degraded plastics. The old exhibition did not have a ceiling, and the vents above the kitchen created a significant dust problem. This issue was particularly problematic considering that many of the plastics within the kitchen are oozing and sticky. The new installation is sealed on the top, and during Mary’s evaluation of the new exhibition six months later, she found a significant decrease in dust accumulation. One problem area was a large gap around one of the glass door covers, but it has since been gasketed to create a better seal.
Mary’s class also found evidence of fading and discoloration in plastics. For instance, the top surfaces of a set of rubber kitchen gloves had turned black, while the undersides remained blue. Mary placed mylar barriers underneath and between problematic plastics to prevent sticking and oozing on surrounding objects. And when the gloves were reinstalled in the new exhibition, the top glove was flipped in order to display the blue side, following the request of the curator.
Mary mentioned the curator’s desire for authenticity within the exhibition and that they wished to have all the original objects on display within the kitchen. While Mary’s class found evidence of plastic degradation, the museum continues to display the degrading plastics in a relatively similar environment as the previous exhibition (although the HVAC system is improved and dust is being mitigated. She also noted that the degrading objects were not causing damage to other objects). Mary’s talk raised questions that many museums and conservators must face, such as authenticity versus preservation? Does displaying original degraded objects or surrogate objects in good condition change the meaning or importance of the work? The answers to these questions may also be different within the context of a history museum as opposed to an art museum.
As I viewed images of oozing spatulas that are not dissimilar to those sold today, one of the questions I had (but didn’t get a chance to ask Mary) is whether there was any discussion with the curators about purchasing surrogate objects either to be displayed now or in the future? Maybe similar objects could be purchased now, while they are still readily available, and stored in more optimal conditions (dark, cold storage?) to be displayed later if needed.
I can’t help but wonder, what will the plastics in the exhibition look like in another ten years? And what would Julia Child think? Bon Appétit?

41st Annual Meeting – Objects Session, May 30 – Three Decades Later: A Status Report on the Silver Lacquering Program at Winterthur by Bruno Pouliot, Catherine Matsen, Jennifer Mass, William Donnelly, Kaitlin Andrews, & Margaret Bearden

For me, this presentation was one of the high points of the conference – a thoughtful re-examination of a typically undertaken protocol.
The Winterthur Museum collection of silver numbers around 11,600 and over 2,000 of those pieces are on display in period rooms and galleries at the museum. Indeed, as characterized by Bruno Poliot, this is a massive task. To reduce wear and handling, silversmith and then conservator Don Heller began a program of cleaning then coating silver in 1974. After a period of experimentation, Don chose to use Agateen Air Dry Lacquer #27, a cellulose nitrate, for coating, suggesting that it should be replaced every 10 years but could last up to 28 years in a museum environment with careful handling. Over 1000 silver objects were thus treated between 1982-1987. While the conservators at Winterthur experimented other coating materials, including Acryloid B-72 and Acryloid B-48N in the decade that followed, research undertaken by conservation scientist Chandra Reedy and others, presented in the OSG Specialty Group at the 1999 AIC annual meeting, indicated that cellulose nitrate prevented tarnish better than acrylic resins, and Agateen #27 became the only lacquer used for silver at Winterthur from 1997 onward.
In 2009, the collection on display was surveyed systematically to assess the condition of the lacquer coatings. They found that:

the lacquer on 42% of the objects had moderate to major problems and would require cleaning and re-lacquering
condition of the coating did not directly correlate with age, method of application, or composition of the silver alloy
condition of the coating did correlation with how well the lacquer was applied and the complexity of the object’s surface
the degree to which the coating had yellowed was difficult to assess, but it was found along with tarnish

In 2011, the museum received a 2 year grant from IMLS for a re-lacquering project. The objects to be treated were grouped into one of three categories:

objects treated in 1985 or earlier,
those with coatings which were defective or otherwise failing,
objects which had never been lacquered before. These were often complex.

Procedures for re-treatment were standardized in order to reduce the amount of application defects. Two conservation assistants were hired for the project, and they underwent a two month training program, working on simpler objects before moving on to more complex ones. Bruno did go into a fair amount of detail about the treatment procedures, and I’m sure his paper will also explore those in greater depth than I will here. One key feature of their procedure is examination one hour and then again 24 hours after application of the lacquer to look for imperfections and iridescence, which would indicate that the coating is too thin. Then a final examination of groups of objects is undertaken 2-3 weeks after the lacquer has been applied to ensure that all solvent has evaporated out of the film and to ensure that the coating is free of defects. Touch-ups to the coating can then still be done, and this period allows enough time for the solvent to completely evaporate, ensuring that it is safe to return them to display.
The team also investigated how Agateen #27 ages, looking both at objects coated with the lacquer in Winterthur’s collection as well as from the collections of two individuals who kept their pieces in home environments. The coatings on the pieces from the private collections exhibited a particular pinkish-brown discoloration, not found on any of the museum pieces. Though analysis of degraded coatings with FTIR and XRF and SEM-EDS provided information about the breakdown of the nitrocellulose polymer and elements found within the degraded films, it was the results of Time of Flight-Secondary Ion Mass Spectroscopy (TOF-SIMS), used to further characterize corrosion within degraded nitrocellulose films, that provided some unexpected results.
In TOF-SIMS, a high energy primary ion beam bombards a sample to ionize molecules on the sample surface. These ionized molecules are then characterized using mass spectroscopy. Looking at the lacquer films from the silver from the private collections, silver sulfide, silver oxides, silver chloride, silver sulfate, sulfate anion and silver cyanide were identified. Except for silver cyanide, all of these corrosion products were also identified in tarnish and corrosion products on uncoated silver.
Bruno pointed out that silver cyanide ranges in appearance from colorless to grey-white in color but could result in the pink-brown color noted in the lacquered objects if mixed with cuprite, which is another corrosion product found on silver objects due to a low copper content. They will next determine whether silver cyanide remains on the silver once the degraded lacquer has been removed and whether this corrosion product is detrimental to the silver.
This pink-brown discoloration was the topic of discussion following the talk. One conservator noted that she had also encountered this condition on lacquered silver from a private collection, and that the condition re-occurred within a few months following re-treatment. She mentioned that Agate, the company which produces Agateen, suggested that this might be a result of exposure to direct sunlight. Another conservator suggested that one potential source of cyanide might be a dip that was used in the past to plate or clean the silver, and that these dips may form complexes on the silver surface which may affect or react with a lacquer treatment. We need to look at how a past procedure may affect a current treatment.
Bruno concluded his presentations with a list of recommendations based on the 550 silver objects completed, and as the team at Winterthur contemplates re-lacquering 500 more pieces in 2015.

The condition of nitrocellulose coatings on complex silver objects should be re-assessed every 5-10 years, given their finding that the majority of the coatings on complex silver objects failed within a 10-15 year time frame.
When considering application of cellulose nitrate lacquers on silver, resources and time to maintain a silver lacquering program need to be considered as the time needed to remove and replace a cellulose nitrate lacquer is significant.
Research into how degraded nitrocellulose lacquer affects silver needs to continue, as does finding alternative options for protecting silver against tarnish.

41st Annual Meeting – Objects Session May 31, “Bringing History to Life: Reproducing a Worthington Steam Pump from the USS Monitor” by William Hoffman, The Mariners’ Museum

One of the most remarkable things about the field of Conservation is its ability to bring together art and science, cutting edge technology and time-honored skills to preserve original historic or artistic works while gaining new insights into how they were produced and making them more accessible to everyone.
These aims seem very much at the heart of the remarkable project presented by William Hoffman in his paper which described the process of studying the manufacturing techniques of a Worthington steam pump excavated from the shipwreck of the historic ironclad USS Monitor which sank in 1862 and building a full scale working replica.
The two original Worthington steam powered water pumps from the Monitor, the earliest known examples of their type, are in remarkable condition considering the nearly 140 years spent in a marine archaeological context before their recovery in 2001. The pumps are nearly finished conservation and will be placed on display at the Mariners’ Museum USS Monitor Center, but the extensive corrosion of the cast iron and copper alloy parts has left them in a fragile condition. The project began to take shape out of the desire to convey the original movement and function of the object to the public in a way which was far more immediate than a computer simulation could achieve alone. I thought this seemed intriguing, and particularly poignant in a digital age when high quality digital renderings have become omnipresent.
Hoffman explained that by conserving, studying and documenting the evidence of the original materials and the molding, metal casting, fabrication, and machining processes used, an approach to making the replica was formulated, using a combination of traditional technical and art metal casting techniques, and the use of modern 3D scanning, CAD, and 3D FDM (force deposition modelling) printing techniques to aid in the pattern and mold making. No less important is the final machining of the parts, made easier by the use of modern computer driven CNC tooling. The resulting replica is well underway and it’s hoped that the fully working replica will be operational in the near future.
Hoffman’s talk was very engaging and made use of digital drawings, animations, and video footage of the replication process, all of which helped to relate a detailed process in a way which was easy for the audience to follow. The enthusiasm of the author and the team of conservators, museum staff, volunteer researchers, 3D scanning and printing specialists, metal casters, machinists, and industry representatives who had helped to make the project a reality came through clearly, as did the high level of interest in the use of the replica pump for multiple educational programs, highlighting the need for conservation of our shared heritage and the information and experiences it can bring to light.

41st Annual Meeting- Textiles + Wooden Artifacts Joint Session, June 1, “Two's Company: Supportive Relationships” by Nancy Britton

Nancy Britton presented several interesting examples of innovative upholstery treatments using carbon fiber support for the underupholstery. She also shared interesting discoveries from examining construction methods and written markings on multiples and sets of furniture from the same workshop and from the same collection.
The treatments used carbon fiber as woven “fabric” sheets which can be cut, shaped, and embedded in epoxy to create very strong, rigid supports for the upholstery layers above. Nancy has used the carbon fiber/epoxy matrix by casting it onto an ethafoam base, casting smaller parts to assemble, and making a one-piece shell. She also makes up flat stock to have on hand which can be cut and shaped more quickly than casting pieces.
Carbon fiber is also available in many other forms from numerous suppliers, including a sandwich board similar to honeycomb aluminum panels, available from the company Protech: http://www.protechcomposites.com/categories/Sandwich-Panels/ (Please note, I am not aware if this specific product is suitable for conservation use.) More information on carbon fiber is available over on the wiki: http://www.conservation-wiki.com/wiki/Carbon_Fiber
Next, I was very interested to see and hear how Nancy examines pieces, and all the information that can be gained even from a bare, deupholstered frame. By looking at the tool marks, hole patterns, and remaining hardware, she has been able to see differences in working method that she feels indicate the work of different craftsmen. One set of furniture she examined had identical materials but differences in working style that suggest they were made in the same shop and time period, but upholstered by different people. Variations in the stitching also provide clues.
Finally, Nancy showed examples of markings (numbers) found on chair frames and upholstery layers of pieces from the Met’s Hoentschel show at Bard Graduate Center. By looking at the marks and comparing them to early photographs of installations at the Met, along with other exhibition information from the archives, she was able to learn more about the upholstery timeline and how the chairs looked in the past.
Nancy’s talk reminded me that careful documentation of an entire piece, down to the smallest and apparently insignificant details, can provide a wealth of knowledge. We may discover new information about the piece’s history, and learn more about past upholsterers, who remain largely unknown.