The obelisk of Pharaoh Thutmose, also nicknamed Cleopatra’s Needle, is New York’s oldest outdoor monument. Matthew C. Reiley, Associate Director of Conservation and Senior Conservator at the Central Park Conservancy, began the talk by providing background information on the history of the obelisk. The stone monument was commissioned around 1450 BCE by Thutmose III to celebrate his 30th year of rule. The red granite was quarried in Aswan and carved with hieroglyphs. It was one of a pair of obelisks that stood at the sun temple in Heliopolis. The monuments were purportedly toppled during a Persian invasion around 525 BCE and were later moved and re-erected in Alexandria by Romans around 12 BCE. In the 19th century, one of the obelisks was given by Egypt to the United States. William Vanderbilt paid for the transportation of the monument to New York City. It traveled across the Atlantic Ocean in the hull of a ship and was raised in Central Park in 1881.
The first condition study and treatment of the monument came in 1885. The study noted damage from freeze-thaw cycles. Salt migration and deposition occurring over time, while the monument was in Egypt, had created microcracks in the substrate. Water infiltrating into these areas and expanding during freezing caused surface loss. Workers removed unstable fragments, and the surface was impregnated in paraffin wax, which over time trapped dirt and pollution. In 1983, the Metropolitan Museum of Art performed a scientific study, which found that the monument was stable and not aging at an accelerated rate.
In 2011, an Egyptian Antiquities official threatened to take back the obelisk, claiming it was not well cared for. This prompted the Central Park Conservancy’s project to document, clean, and stabilize the monument. Photographs were taken and color annotated to document condition issues. Cleaning tests, using aqueous methods, micro-abrasion, and lasers, were performed in order to find a suitable method for removing years of accumulated soiling and atmospheric pollutants that obscured the carvings. Based on these tests and in situ mockups, laser cleaning was chosen because it was controllable, effective, and did not damage the stone.
For the second half of the talk, Bartosz Dajnowski, Vice Director and Objects Conservator at the Conservation of Sculpture & Objects Studio Inc., described the laser cleaning methods. He listed some of the benefits of laser cleaning: no chemicals, no abrasives, no loud noises, and no public hazards or contamination to the surrounding areas. Unlike a laser pointer, the beam of this laser is focused to a point and then it spreads out so that the radiation diffuses past the focal point. The cleaning process is called laser ablation, and it works discriminately as it excites one material so that it separates from the substrate. Since laser cleaning is not a mechanical process, it is safe to use on fragile substrates. Bartosz noted that it is important to use the correct settings because if the laser is used incorrectly, it could damage the substrate, for example by melting bronze or shattering quartz and melting inclusions in stone. He also pointed out that adding water to a surface during laser ablation has a micro-steam cleaning effect as the laser turns water into steam. The water also helps reduce the effects of plasma formed by the laser, minimizing the possibility of phase changes in the iron within the stone.
Bartosz spoke about his prior experience and research with lasers, including work done during his graduate studies at Winterthur. Extensive testing and analysis was done on stone samples before laser cleaning began on the obelisk. Small fragments that had previously fallen off of the obelisk were cleaned and then examined by George Wheeler at the Metropolitan Museum of Art to confirm that safe laser cleaning parameters were being used.
Seven lasers were used to clean the entire stone monument and the four bronze crabs around its base. One of the lasers, called the GC-1, Bartosz built himself using a new design. With the other lasers, the pulses are emitted as line scanning, with a mirror alternating left and right, so the pulses come out like a machine gun firing back and forth. This creates hot spots at the edges, which can result in overcleaning or damage. Optical shields and other methods can be used to cut off the hot spots, although this decreases efficiency. In Bartosz’s new design, the laser pulses are emitted in a circular ring pattern, so the beam is constantly moving around in a circle. In this formation, there are no hotspots, and when the instrument is moved across the surface, the coverage area is exposed twice, which increases efficiency. Since this unit is also smaller, Bartosz was able to take it up to the top of the scaffolding. As others on his team used the line scanning lasers and worked from the bottom of the monument up, Bartosz worked from the top down. With his new laser, he was able to clean the same sized area in half the time!
With lasers, the level of cleaning is controllable, and Bartosz mentioned that the team was asked to try leaving some soiling in the recesses of the carving to increase the legibility of the glyphs. However, the soiling was uneven, and the carving had suffered previous damage, so it was not always easy to distinguish. An overall cleaning was carried out, although a few areas of soiling were left near the top of the monument for future analysis.
Following laser cleaning, fragile and unstable areas of the stone monument were consolidated. The 3,500 year old, 220 ton obelisk now stands cleaner and more stable for the future. In a fitting end to the talk, Bartosz noted the appropriateness of using light to clean and revive an ancient monument that was originally built to honor the sun.
Category: Architectural Conservation
43rd Annual Meeting- Architecture and Wooden Artifacts Joint Session, May 14, “How to Salvage your Historic House Museum after a Car Crash: The Marrett House Emergency Preservation and Conservation Project” by Benjamin Haavik and Alexander M. Carlisle, Historic New England
When a drunk driver crashed into the parlor of Marrett House (1789) in Standish, Maine, the staff of Historic New England was able to see first-hand how well their disaster plan worked!
The damage was serious: clapboard smashed, wall studs snapped, wainscoting was knocked out, and furniture was displaced inside the room.
Local staff were on the scene quickly to secure the area. A team drove up within hours of the crash, to add temporary supports for the 2nd floor and to board up the hole in the house. The insurance company was called, and the policy was able to cover some recovery costs.
With such extensive damage, recovery was not straightforward. The floor carpet (dating to 1857) was undamaged, and due to its size, it was rolled and boxed to remain in the room during construction work. Furniture and objects had been removed from the room immediately, to be treated and stored. The house remained open for tours during the entire process.
The conservation and restoration of the structure was carried out with the goal of maintaining as much of the original materials as possible. The 1857 wallpaper and paint finishes were protected in situ. Where new support beams were needed, the modern additions were marked with copper tags to identify them as non-original. Plaster, lathe, and wainscoting were replaced; in the end, only spot retouching of the paint on the paneling was necessary.
Only three pieces of furniture were actually damaged (two chairs and a card table), and one vase fell during the crash. No pictures fell off the walls, and the rug was totally fine. Overall, they feel lucky that the damage was not worse.
Here are some tips they shared for disaster response:
-photograph the damage before starting recovery: this is good documentation practice and can help with insurance claims
-don’t throw anything away: a small bit of veneer from the damaged table was later discovered among the wood splinters and debris swept up during recovery (and saved in a box), and was able to be reattached
-make sure the emergency telephone tree makes sense: HNE is geographically far-flung, and in this case the first people called were NOT the closest to the scene
43rd Annual Meeting – Architecture Specialty Group – May 16, Mid-Century Modern Wood Issues at the Weston Havens House by Kitty Vieth and Molly Lambert
Kitty Vieth, a senior associate at Architectural Resources Group, presented the work required to rehabilitate the most fragile structural conditions of the Weston Havens House. Molly Lambert, a conservator in private practice, discussed techniques she used to remove tide lines from interior cedar paneled walls.
The Weston Havens House is a Mid-Century Modern construction designed by architect Harwell Harris and built in 1941. It sits in the hills of Berkeley and has an 180-degree view of the San Francisco Bay. Weston Havens was the only owner of the house until his death in 2001. He bequeathed the property to the University of California Berkeley who now uses the house for visitors.
The house features a modernist design with upper and lower levels cut into a hillside. A curvilinear stair leads to the lower floors. There are two guest rooms with private terraces. The house contains original finishes at are intact. Kitty Vieth was brought in to evaluate the conditions of the materials and all building systems.
Upon evaluation, two high priority projects were defined. The first project was the Pedestrian Bridge that was in a state of near collapse. The bridge displayed a keel type construction with paired studs. Slow growth Redwood found in the Berkeley area was used to construct the Bridge. All of the wood showed deterioration, especially the structural components. Fortunately, the main beams were still structurally sound, but Vieth was not able to save the rafters and studs. The bridge was reconstructed using long slow growth of redwood that is already beginning to fade to grey and better match the original materials. A finish was used to protect the reconstructed bridge.
The second priority was the East wall and roof area. The seismic activity of the area was considered. Redwood boards were greyed, worn and cupping in some locations. Vieth consolidated and rehabilitated the windows and walls on East wall.
Molly Lambert spoke next about earlier work she undertook in the house when Weston Havens was still alive. This and other modernist structures often have redwood paneled interiors. When roofs leak tide lines form on the interior panels. Molly did two different campaigns to repair tannin tide lines on the interior of this house. She was able to get 80-90% of the tide lines out. Tannins in the wood migrate with water causing the darkened lines.
Her technique was as follows:
- Wipe down the entire panel with wet cotton PVOH sponges (cellulose sponges) with grain.
- Harvest some of the tannins with a swab using distilled water or spit and transfer to needed areas.
- Don’t take too much of the tannins away.
- In-paint with a tannic acid mixture as needed.
43rd Annual Meeting – Architecture Specialty Group – May 15, Concrete Actions to Extreme Risks: Conservation of Humberstone and Santa Laura Saltpeter Works World Heritage site in danger, IQUIQUE, Chile, Alicia Fernandez Boan
During the Architecture Specialty Group Session, Alicia Fernandez Boan focused on the conservation efforts and needs for two World Monument sites that represent the salt peter mining era in Chile.
The salt peter works are remains of human activity in the Atacama desert. Operation began as part of Peruvian territory in mid-19th century. They were declared world heritage sites in 2005. Humberstone and Santa Laura represent over 200 salt peter works that once existed. The Atacama desert has a temperature extremes from 0 deg c at night to 40 deg c midday, which takes it’s toll on the built environment. The cultural landscape is made up of the structures and surrounding site that is formed due to the accumulation of byproducts of the mining efforts.
At Humberstone, the structures and buildings of the community remain — church, school houses. Alternately, Santa Laura is representative of the industrial sectors found in saltpeter works. The materials are exposed to extreme weather. The structures are also exposed to salts and chemicals that were part of the production. There are dozens of rust colored structures. They include generalized corrosion and galvanized losses.
In order to maintain these sites, several factors must be considered. The conservation of urban sites requires establishment of commercial activity so that the site can be self-sufficient and sustainable. Therefore rehabilitation, recycling, controlled use, and the reoccupation of the territory is greatly needed. Use of these sites as museums documenting the industrial age of salt works is currently happening but more is needed. Rehabilitation, recycling, controlled use, the reoccupation of the territory works will be necessary for the long-term preservation of the sites.
From a conservation standpoint, the sites have conservations needs but they offer the possibility of a conservation field laboratory. This is a place where cleaning tests and environmental aging tests could offer substantial information to the preservation community. The sites offer the ability to study corrosion on a monumental scale under extreme weather conditions.
43rd Annual Meeting – Opening Session, May 14, Concrete Conclusions: Surface treatment Trails for Conserving the Miami Marine Stadium by John A. Fidler, Rosa Lowinger, et. al.
“This presentation by John A. Fidler and Rosa Lowinger focused on testing cleaning methods for removal of graffiti from concrete surfaces at the Miami Marine Stadium. The work is being undertaken by the Friends of the Miami Marine Stadium with funding by the Getty Foundation.
The stadium is an excellent modernist structure designed by the Cuban-American Architect, Hilario Candela. The building includes a 326 foot-long cantilevered thin shell concrete roofline that is among the longest in the world. The Stadium was created for speedboat racing but was also used as a concert venue, and featured artists such as Jimmy Buffett, Sammy Davis Jr, and more. The stadium is owned by the city. It was closed in 1992 after Hurricane Andrew and has fallen into a state of disrepair. It has become the central site for graffiti artists in the Miami area and the surfaces of the stadium are covered with multiple layers of graffiti.
Because of it’s unique and original mid-century design, the Miami Marine Stadium is the recipient of the Getty Foundation Keeping It Modern Initiative funding. This is one of nine structures to have received this type of grant. This funding has allowed for testing graffiti removal methods and evaluating concrete repair materials for the project. This 12 month testing phase is due to be completed this summer, but the project will be on-going.
The Friends of the Miami Marine Stadium are working diligently to save this structure from a city demolition order that was issued in 1993. There is concern about the welfare of the deteriorating concrete and the structure’s hurricane resistance. The project requires both civil engineering expertise and conservation skills. In addition to materials conservation issues, the cultural and social use of the site as a graffiti sanctuary must also be addressed. Repair of the concrete in many places will require the removal of many of the graffiti works. While much of the graffiti designs are undertaken using acrylic or polyurethane enamel car touch up paint, there are more than 200 types of paint materials used to create the graffiti art.
The project will require graffiti management for current and possible future tagging. Initial meetings were held with the graffiti artists to convey that there is intent to honor the role of their work, to record the work, and to provide creative ways to archive or show the work. In the future there may be walls placed for graffiti artists to continue their efforts.
Current conservation research efforts are focusing on three lines of study – graffiti removal, anti-graffiti protection, concrete repair. Graffiti removal is focusing on both mechanical and chemical methods of removal. Mechanical techniques include dry-ice abrasion and/or laser cleaning. This may also be followed by chemical methods such as Dumond’s Smart Strip Pro, or custom chemical blends using 5% formic acid and benzyl alcohol. To protect surfaces from new graffiti additions, anti-graffiti barriers are being tested. These treatments may include Dumond Chemical Watch Dog, as well as Keim, and Prosoco products.
Concrete patch repair is focusing on stable long-term materials. Worldwide over 90% of concrete repairs fail within 10 years. Thus, it is important to test potential patch materials in actual environments prior to treatment. Also, the surface textures and finishes will be a challenge to conservators. Materials selected for testing include:
- SIKA Mono-top
- BASF Emaco Repair
- Edison Coatings System 45
- Cathedral Stone Jahn M90
- Custom Mixes
Results of this research will both guide the treatment of the Miami Marine Stadium and serve as a guide for the treatment of other mid-century modern concrete buildings and structures.
43rd Annual Meeting – Joint Session: Architecture and Wooden Artifacts, May 14, "Furniture/Interiors Conservation Training in China by Gregory Landrey"
The third class of students has just been accepted into the CRAFT Program (Conservation Resources for Architectural Interiors/Furniture and Training) at the Palace Museum/Forbidden City in Beijing, co-sponsored by World Monuments Fund, the Palace Museum and Tsinghua University, where Greg Landrey worked as Conservator in Residence last fall. Landrey began his lecture by introducing the city of Beijing with a focus on the layout of the Forbidden City, in particular the Qianlong Garden (a cluster of 28 modest buildings in the northeast corner), as these interiors and their furnishings are used as teaching tools and selectively treated by the students in the program. The current student class size is approximately twelve students, and Landrey spoke through an interpreter when teaching. He also introduced the team of American conservators who have been teaching at CRAFT, and stressed that collaboration with the team was extremely important throughout the teaching process. Chinese experts also teach courses on wood identification, furniture history, and architectural history and preservation.
Landrey showed numerous photographs of the students at work in their classroom and lab, which appeared to be a large, modern, and filled with natural light. His curriculum began with conservation ethics and theory, using the “three-legged stool” example as a teaching tool. Other subjects included the nature of wood, building hygrometers to see wood movement in action, wood technology, loss compensation, and casting. Landrey said that learning went both ways, because the students shared their knowledge of craft approaches and techniques with him throughout the semester. Treatment was also a teaching tool, with the students working as a class to document, analyze, and clean a three-part screen from the Qianlong Garden quarter of the Forbidden City. Landrey also had the students carry out drawing exercises each week to hone their drawing and observation skills, and he showed some particularly lovely examples to the audience. Field trips were taken to museums in Suzhou, as well as to the studio of a traditional lacquer artist and brocade museum with active looms.
Landrey had the students regularly read the AIC Code of Ethics as well as the Principles of Conservations of Heritage Sites in China, and expound on passages they felt were particularly meaningful to them. The student answers were shared with the audience as they were very insightful and showed how much they had learned. The goal of the program is to produce conservators to serve projects in China, and eventually the CRAFT curriculum will be entirely taught by Chinese conservators and scholars.
This talk was peppered with wonderful images and insights into Landrey’s life in Beijing, including the lively chaos of the city streets, Tai Chi being practiced by the students and staff in the morning, and the reverence the culture has for trees, which apparently made him feel a little bit more at home.
43rd Annual Meeting – Joint Session: Architecture and Wooden Artifacts, May 14, "Analyses of the Architecture of Wooden Churches from Buzau County, Romania by Necula Elena-Theodora"
The speaker began with some general information about Romania, where more than 12,000 historical wooden churches survive, eight of which are UNESCO sites. In the north, one distinguishing feature of the churches is a bell tower atop a sharply sloping roof, for drainage due to the abundant rainfall in that area. In the drier south, there are no bell towers and the roof is lower, more in the style of a traditional Romanian house. Focusing on Buzau County (located between Moldova, Transylvania and Wallachia), most of the churches are in the northwest region, with thirty-two historic churches of particular importance. The speaker carried out in-situ investigations of these churches in the summer of 2013, and these investigations appeared to consist of archival research, visual investigation and documentation. Most of the buildings are of wood beam construction with a rectangular floor plan that follows the plan of the Orthodox Church, and include a porch at the front entrance. Many contain interior paintings on sheet metal or on wood, executed in oil (on metal) or tempera (wood). Some exterior decoration survives in the form of shallowly carved motifs. The speaker spent a few minutes presenting each church, usually showing an overall exterior photograph, a floor plan, any specific construction details that made it unique, as well as an abbreviated history of its restoration. Some images of the interior paintings were also shown. The state of conservation of the churches was not discussed, although it was a question afterwards. The speaker answered that while some of the churches are still in use, most are completely abandoned and in need of care.
AIC 43rd Annual Meeting- Architecture Specialty Group Session, May 16th: “One Piece at a Time- The Repair of Felt-Bases Sheet Flooring at Johnny Cash’s Boyhood home in Dyess, Arkansas” (Christina Varvi)
Christina first discussed the location- a New Deal planned farming community of 500 homes. It is now the only surviving home from the community and the town now has only 388 residents today. The home was acquired by the Arkansas Heritage Sites if Arkansas State University, located an hour and a half away. The home was furnished with 2 rooms of original flooring and objects owned by the family augmented by furniture dating to the time and 2 rooms of floor covering belonging to nearby Dyess Colony houses. The house was to be opened as a historic site for visitors in August 2014
RLA (Rosa Lowinger & Associates) was brought in at the end of the project to conserve the original floor coverings. Consideration had to be taken into account that the living room flooring would be walked on. There was little time and budget due to this being an add-on to the project at the last minute. The original estimate was double what the project could afford. Discussions led to a scale back in the project and priorities were set to what was most important to happen right away. Treatment was mostly confined to the 2 original-to-the-house floorings- those in the living room and Johnny Cash’s boyhood bedroom. Treatment was confined to cleaning (vacuuming and surface wet cleaning), stabilization of tears (on back with Japanese tissue and B72), fills and in-painting on living room flooring, and varnish (applied by brush) to protect the surface of the flooring. The non-original-to-the-house flooring was not varnished. Recommendations for now are furniture pads to protect the floor underneath, recommendations for visitors to remove shoes and use booties in the living room and roller shades to reduce light during off hours. Next steps are to raise additional funds to finish work on the floor, work on additional buildings on site (outlying farm buildings) and to raise funds for a visitor center.
There were many complexities to this project: the area was very rural, there was no running water in the house, the house was climate controlled but not airtight, no shops to be able to get supplies and the client was an hour and a half away. Everything had to be brought in. Additionally since the floor covering project was a last minute addition, furniture was already in place and could not be moved out of the house. With careful planning, much more was accomplished in the time given than was though possible and the treatment was a success.
NCPTT announces Mid-Century Modern Structures: Materials and Preservation 2015 Symposium
![By Daniel Schwen (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons](http://www.conservators-converse.org/wp-content/uploads/2015/01/St_Louis_night_expblend.jpg)
The NCPTT symposium on the materials and preservation issues of Mid-Century Modern Structures will be held in St. Louis, MO, on April 14-16, 2015. Go to ncptt.nps.gov to learn more. Register now!
This three-day symposium will feature a keynote speech on preservation of Mid-Century Structures by Gunny Harboe, plus 23 lectures, a panel discussion, poster session, and tours by leading professionals from across the country.
Major topics include:
- Preserving the Gateway Arch
- Establishing an appreciation for mid-century structures from ranch houses and commercial buildings to architectural icons
- Understanding preservation and materials issues in mid-century structures including metals, glass, concrete, and fiberglass
- Learning from case studies of unique buildings such as the Farnsworth House, Fallingwater, and the Knapp Centre
Distinguished speakers include: Justine Bello, David Bright, Mary Reid Brunstrom, Amanda Burke, Bradley Cambridge, Barbara Campagna, David Fixler, Ann K. Dilcher, Christopher Domin, Carol Dyson, Evan Kopelson, Joshua Freedland, Holly Hope, Catherine Houska, Nancy Hudson, Mary Jablonski, Pamela Jerome, Stephen Kelley, Walter Sedovic, Laura Kviklys, Alan O’Bright, James C. Parker, Joe Sembrat, Robert Silman, Tyler Sprague, Claudette Stager, Anne Weber, Ashley Wilson and more.
A special public lecture on Monday, April 13, at Washington University in St. Louis will feature Kevin Roche, Susan Saarinen, and Robert Moore. Video recordings of lectures and published proceeding will extend the symposium to a broad audience. Brought to you by the Friends of NCPTT, the National Park Service, the Jefferson National Expansion Memorial, the American Institute for Architects St. Louis, Washington University in St. Louis, and the World Monument Fund.
Read more at http://ncptt.nps.gov/events/mid-century-modern-structures-2/.
42nd Annual Meeting – Joint Architecture and Objects Session, May 29, "The Cultural Production of Tourism at Lake Tahoe: Exploring How Cultural Heritage Preservation Is Impacted By Tourism," by Catherine Magee
This paper was a departure for a specialty group presentation in that it focused not on the conservation or technical study of material culture, but on the creation and consumption of cultural narratives and landscapes. Magee noted that conservation work informs and perpetuates stories about people, places, and things, and made the point that conservators are generally comfortable thinking about our work in the context of education, science, and academic scholarship. But she proposed the idea that we must also consider our role in the broader context of tourism, since the primary products of our work – conserved objects and sites – are most often intended for consumption by the general public, also known as tourists.
Her paper included a brief overview of tourism studies, examining the impact of tourism on different kinds of sustainability: economic, ecological, and cultural. The bulk of the paper was spent illustrating the latter point, looking at the ways tourism influences our perception of history and heritage by creating hybrid tourist/cultural heritage landscapes and influencing cultural memory.
Magee used two examples from her doctoral research, which focuses on the landscapes and material culture of the Washoe people in the Lake Tahoe area. The first example was Cave Rock, a pilgrimage site of major spiritual significance for the Washoe. The site was progressively destroyed by tourism, evolving from a culturally significant tourism site, to a pathway for a road, to a mecca for rock climbers. The second example focused on an iconic Washoe basket form, the degikup, and its most famous creator, Dat-So-La-lee. Magee examined the shared mythos of Dat-So-La-Lee and the degikup in detail, revealing the stories, and the basket form itself, to be products created for tourism.
The role of the conservator in shaping the destiny of a site like Cave Rock or the narrative surrounding iconic artifacts and artists like the degikup and Dat-So-La-Lee was not explicitly discussed. It’s not difficult, however, to imagine the complexity inherent in conservation decision-making for the kinds of tourist-hybridized sites, objects, and narratives explored in this paper. Magee argued that we conservators will discharge our responsibilities best if we develop a better awareness of our role in the cultural production of tourism. With that awareness, we can improve our agency in the process and generate better outcomes for sites, objects, and the communities we serve.