Category: Architectural Conservation

39th Annual Meeting, ASG Morning Session, June 2nd, Student Papers, “Rediscovering an American Master: The analysis and proposed treatment of the decorative plaster ceiling of Robert Winthrop Chanler’s Gertrude Vanderbilt Whitney Studio, New York” Lauren Vollono Drapala, University of Pennsylvania

Lauren’s presentation introduced me to a true treasure hiding out in my downtown New York City neighborhood at 8 West 8th Street on Washington Square. In what was once the original location of the Whitney Museum lays the intimate studio retreat of patroness to the arts, Gertrude Vanderbilt.  Lauren’s focus on this room was to conduct historic research, assessment, analysis and documentation of the decorative ceiling created by artist Robert Winthrop Chanler.  What first appears as textured white plaster ceiling is actually a highly detailed bas relief plaster composition that still has some indications of paint. [PHOTO].   Like Angela’s Curmi’s talk before, Lauren knew there was an original decorative finish below the surface based on similar works by the artist, documentation, and cross-sectional analysis, but was having problems with accessibility to the paint after the ceiling had been overpainted white, most likely due to unaddressed failings of the plaster and paint over time.  Lauren’s goal was to eventually discover a means to safely remove the overpaint  and conserve the original paint below. I was rooting for her!

 

After creating high res photodocumentation of the ceiling, including an overall raking light image to accent the relief, Lauren mapped the condition and motif of the ceiling to aid with her investigation.  Lauren also visited other sites with similar work by the artist at Peebles Island and Vizcaya Museum to note pigments and decorative effects he employed at a similar time.  Lauren’s paint analysis [PHOTO]revealed that the newer layers of paint were bound more strongly to the original paint than the original paint was bound to its plaster substrate; the removal of the overpaint was not looking favorable.  Lauren was even given a detached portion of the ceiling to test  overpaint removal gels on, unfortunately with little success.

 

Following what looked to be a disappointing end to all of her hard work, Lauren took it a step further.  She made mock up panels of the ceiling based on her research and analysis to get a better idea of the surface then combined that information from her analysis to propose what it “May have once looked like”.  Here is the initial result of her efforts [PHOTO].  I’m still rooting for this project.  In the meantime if you are interested in learning more, read Lauren’s thesis: http://repository.upenn.edu/hp_theses/151/

39th Annual Meeting, ASG Morning Session, June 2nd, Student Papers, “Non-Destructive Investigation of Concealed Gilding in Architecture” by Angela Curmi, Columbia University

As an objects conservator, I tend to overlook the decorative walls of a historic house, focusing instead on the surrounding 3D aspects.  Angela’s talk really made me stop and think about the walls, as not only a significant work in themselves, but also as a record for changes in style and taste.  However the problem becomes, how do you look at certain aspects of previous wall decoration without removing the layers of historic paint?  Furthermore, how do you look at the overall motif of an entire room, without removing paint from the entire room?  Angela’s thesis from her studies at Columbia University focused on non-destructive methods of detecting gilding under layers of paint.

 

For her research, Angela created mock-ups of gilding motifs using gold, silver, and aluminum leaf under 3-5 layers of various paints (enough to provide visual coverage) and relied on infrared reflectography, infrared thermography, and eddy currents to see if gilding could be detected non-destructively.  The pigments of the paints can interfere with the ability to image so Angela chose historic lead white paint,  calcimite paint, and modern ‘Latex Paint’ along with burnt sienna, chromium oxide, yellow ochre, and Prussian blue [PHOTO ] on prepared wood panels [PHOTO].  For equipment Angela used a modified Kinamax nightvision webcam, modified Nikon Coolpix IR Camera, and Indigo Systems INGaAs NIR camera to test the Infrared Reflectography, as well asFLIR ThermaCAM P640 and FLIR Inframetrics InfraCAM to test the Infrared Themography [PHOTO].

 

Several years ago I had to attend a conference on IR imaging in an attempt to find the most practical model for my lab, so I empathized with the literature and technical data that Angela must have had to sieve through in order to find an appropriate model for her imaging.  Her results were much like I experienced, there is no ‘best’ suited for a conservator’s needs.  As Angela stated there were drawbacks to all systems, either in their range of wavelengths, ease of software use, or the quality of the image produced.   She did not find success with Thermography, mostly because of the inefficiency of heating a large space evenly to get the image.  Reflectography was more promising with the best results achieved with the Indigo INGaAs NIR camera, though its use is not necessarily practical based on cost.  The most practical model appeared to be the Kinamax model, an affordable, easily used modified web camera, the result of collaborative research from Elizabeth Nunan and Greg Smith at Buffalo State College.  For more information and purchasing of your own model go to Elizabeth’s website:  http://www.aandnartconservation.com/infraredsensitivewebcam.html

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39th Annual Meeting, ASG Morning Session, June 2nd, Student Papers “A Technical Study and Conservation Proposal for the Glass Mosaic Decoration of Villa Caparra in Guaynabo, Puerto Rico” by Yaritza Hernandez Nieves, University of Pennsylvania

I had never heard of the Villa Caparra before Yaritza’s talk.  Yet, after her presentation I was left with the urge to take a summer vacation to Puerto Rico to see this beautiful example of cement embedded glass mosaics; both for their personal design elements, and their intriguing conservation issues.  Yaritza presented her thesis from the University of Pennsylvania in which she ambitiously investigated the materials, fabrication, installation, and conservation issues associated with this 20th century architect’s designed home and studio.  What was once a showcase home, had become the victim of urban encroachment and overall neglect.  With a new interest by Puerto Rico in making this location a historic museum, Yaritza’s research and documentation will certainly ensure conservation intervention will be a success.

 

All of the mosaics were comprised of glass tesserae laid in a reinforced concrete substrate, which at the 1927 construction was a considered a modern material and new technique.   Yaritza surveyed the mosaics, classifying 3 types of flat glass used, their mosaic techniques, the location within the building’s structure, and the conditions of the glass in these areas.  As an objects conservator the amount of information from this survey seemed overwhelming at first, but Yaritza quantified her data with mapping software then combined XRF/SEM analysis to determine what the conservation problems [PHOTO] were, and her recommended for treatment.

 

The main damage was from the Portland cement substrate, whose caustic components were solubilizing the silica components of the glass.  This problem was only exacerbated by compression cracking and losses of the tesserae, which provided addition inlets and outlet s for water infiltration and evaporation. The movement of water resulted in the movement of the caustic cement components and ultimately the deterioration of the vitreous  glass.  Yaritza concluded by giving a few initial recommendations of conservation treatment [PHOTO] as well as avenues for additional research. This was a really a well researched paper that presented a wealth of research in a very limited talk time.  Well done Yaritza!  See you all in Puerto Rico soon!

AIC’s 39th Annual Meeting – ASG Session, June 3, “Conserving a Space for Commemoration: Trinity Cathedral Burial Ground Renewal” by Teresa Duff, Post-Graduate Fellow, University of Pennsylvania’s Graduate Program in Historic Preservation

Teresa Duff presented the conclusion of a twenty-year, three-phased conservation project by the University of Pennsylvania Graduate Program in Historic Preservation at the Trinity Burial Ground in Pittsburgh, PA.  The first phase, begun in 1990, entailed a condition survey and pilot testing program for the conservation of grave markers in the cemetery.  In 2000, students from the University of Pennsylvania performed the second phase of testing, and in 2007-2008, Duff and her colleagues began Phase 3, which was in conjunction with a landscape renewal by Andropogon.

Duff explained that the site was a Native American burial ground that was adopted by white settlers in 1779.  In 1822 the first church was erected on the site, and the current Trinity Cathedral was constructed in 1872.  The grounds contain 155 stones along with burial-marker fragments.  Duff and her colleagues mapped the site and numbered each plot, and created color-coded layers for conditions, treatments and the history of markers.  They built a site-specific treatment platform for the on-site conservation of markers, and completed the conservation treatments begun in 2000.  Treatments included cleaning and removal of biological growth, epoxy repairs for blind delamination and cracks, pinning with fiberglass pins, carbon fiber strap reinforcement on the back of some markers, excavation and resetting of partially buried or at-risk markers, and the burial of markers who had lost their material integrity.  Fragments were displayed on the exterior walls of the church.

The author provided detailed information about treatments and products, but I would have liked to have learned more about the history of the site, the types of stones and carving represented in the burial ground, and the rationale behind some of the treatments.  There were many questions following the talk about the landscape renewal by Andropogon, particularly the native grass they selected which does not need to be mowed.  It was a well-organized presentation with good visuals and detailed information.

 

39th Annual Meeting – Architecture/Research and Technical Studies Joint Session, June 3, Consideration of Infrastructure in the Assessment of Historic Fountains by Thomas J. Podnar

Thomas J. Podnar opened with a picture of an anonymous fountain to illustrate the beauty of these structures and their ability to bring beasts together (displayed by horses drinking from the fountain). The talk consisted of three case studies which are summarized below.

The Probasco Fountain in Cincinnati, Ohio (c. 1887) was the subject of the first case. The fountain consists of Quincy granite with a polished bowl and a bronze top. The fountain was located precariously close to an existing roadway, and Podnar was hired to evaluate the condition of the fountain and explore the feasibility of moving it to a safer location. During an investigation of the interior cavity, he found a water main running through the chamber and an electrical box, which was added for display lights. Research of historic photographs revealed that the water display had been diminished and that it was missing elements such as drinking cups. In the end the city decided that it was cheaper to move the alignment of the road (slightly), and the fountain remains in the original location.

The second case study subject was the Athena Tacha in Cleveland, Ohio (c. 1985). The stepped granite fountain was designed to be ½ wet and ½ dry (the latter for students to perch upon). After running for eight years, the fountain was shut off due to issues with water leaks. A condition assessment found that the adhesive sealant, used to control water, had failed and resulted in water leaking to the dry side. Mineral deposits were also found on the stone’s surface, other conditions included broken pipes, corrosion, and inadequately sized equipment. The client also shared photos taken during the installation process, and Podnar noticed that it was the middle of winter. Low temperatures had also caused poor bonding of the stone to the continuous mortar bed. A full re-installation and equipment upgrade was recommended and subsequently executed. Stones were removed and labeled, and when re-installed provisions were made for water seepage to flow to the pool (at the base) and stainless steel clips were added to reinforce connections. Custom-fit pieces of sheet metal were installed to separate the wet and dry sides. The mechanical system was fully replaced (upgraded) and the access grate was designed to match the existing (granite) in galvanized metal, rather than stone, to facilitate maintenance with a lighter unit.

Voyage of Ulysses on Sixth Street in Philadelphia (c. 1977) was the subject of the final case study. The stainless steel fountain was fabricated by Lippincott and designed by David von Schlegell. During the condition assessment, Podnar found that the clear coating (applied to the metal’s surface) is failing and that the water display has been diminished (when compared with historic photographs). The fountain installation is located over a parking garage, and is leaking into it. The mechanical system consists of separated pumps for the two different display elements (high water throw on one side and a continuous waterfall on the other). Other findings include that the screen strainer has never been removed during maintenance and that over the years pumps were replaced with smaller ones. Podnar shared historic photographs taken during fabrication of the artist testing the water flow at Lippincott, emphasizing the importance of water flow in this fountain’s design. Conservation treatments are planned and have not yet been executed.

39th Annual Meeting – Architecture Session, June 3, “Assessment and Characterization of the Architectural Metal Finishes at Fort Moultrie: A Successful Student-Scientist Collaboration” by Stéphanie A. Cretté, Lisa M. Nasanen and Néstor G. González-Pereyra, Clemson Conservation Center, Warren Lasch Laboratory; and Frances H. Ford, Clemson University/College of Charleston Graduate Program in Historic Preservation

Amelia Millar from the Clemson University/College of Charleston Program in Historic Preservation, and Stéphanie A. Cretté from the Clemson Conservation Center presented a two-part paper on a graduate-level project at Fort Moultrie National Monument near Charleston, SC.  Millar presented the student portion of the work, while Cretté presented the analytical research.

The project entailed a survey of metals in a portion of the Fort Moultrie site, owned by the National Park Service.  Students from the Clemson University/College of Charleston program performed a survey of all existing metals, both architectural metals and the metal objects on site, and assessed the condition of the metals.  They took paint samples to determine the chemical composition of the paint so that NPS can develop a strategy to safely remove any lead-containing paint while preserving the metal substrates.  The students did most of the field work and tested paint-removal methods, then collaborated with scientists from the Clemson Conservation Center on SEM-EDS and Raman analysis of the paints.  Most of the scientific portion of the presentation was about the analytical techniques and why they were used for this application.

The paper was interesting, but I would have liked to have learned more about the researchers’ findings and the various treatment recommendations put forward by the students.  It would have also been interesting to learn whether the NPS has implemented or plans to implement any of the student recommendations.  Nevertheless, it was a good collaborative project that seems to have benefited the students and scientists alike.

 

39th Annual Meeting – Architecture Session, June 3, “Comparative Study of Commercially Available Rust Converters” by Jason Church, Anna Muto and Mary F. Striegel, National Center for Preservation Technology and Training

Jason Church from NCPTT presented a useful paper on commercially available rust converters.  He explained that rust converters are a chemical treatment that converts iron oxide into a more stable product, though this product varies depending on the chemical composition of the rust converter.  Church and his colleagues started with the 1995 Canadian Conservation Institute study of rust converters, but found most of the products to have been discontinued or available in new formulations. This led the team to perform their own experiment.

Church et al., selected four commercial products of varying chemical composition: Ospho (phosphoric acid base), Rust-oleum Rust Reformer (tannic acid base), Corroseal (gallic acid base) and RCx427 (oxalic acid base).  The four commercial products were selected on the grounds that these products were readily available, were top sellers, and could be purchased in sufficiently small quantities so as to be accessible to homeowners or for small conservation projects.  Church and his colleagues also tested the CCI-recommended custom formulation of tannic and phosphoric acid, which several objects conservators they polled still claim to use.  NCPTT staff tested the five rust converters on new A36 carbon steel that was naturally weathered.  They subjected each of the test samples to artificial weathering and measured the samples for color changes and active corrosion every 250 hours for 1000 hours total.  They found that the Rust-oleum product had the least color change and most stable surface of the five products tested, though the efficacy of each product tested was quite varied.  Church mentioned that their testing is not complete.  They continue to push the Rust-oleum product to metal failure through extended artificial weathering, and will also test the new aerosol version of that product.  They also plan to perform outdoor accelerated weathering tests on the five products.

The presentation was interesting and informative, as is characteristic of studies done by NCPTT.  I like that their experiments are developed for conservators, but the results are accessible to anyone.  The information presented in this talk will surely broaden the body of knowledge for architecture and objects conservators and will be useful for homeowners and maintenance workers.  Following the talk, moderator Patty Miller recommended that they eventually expand their testing scope to include conservation-grade products and less readily available materials.  I concur, and I would encourage Church and his colleagues to publish their findings.

39th Annual Meeting – Architecture Session, June 3, “Like Twinkling Stars: The Technical Analysis of an 18th Century Ceiling from Damascus, Syria” by Kirsten Travers, Winterthur/University of Delaware Program in Art Conservation

In the summer of 2009, Kirsten Travers and LeeAnn Barnes Gordon performed documentation and conservation treatments on the ceiling of the Turkish Room in Doris Duke’s Shangri La estate in Hawaii.  The ceiling was originally commissioned in 1797 for the Quwwatli family reception room in their home in Damascus, Syria, and was made using a technique called adjami.  The author provided a brief but thorough explanation of the traditional material, which, if I am correct, is made by nailing together thin slats of wood, filling gaps and holes with fiber, applying raised gesso ornament followed by layers of metal foil, tinted glazes and paint.  The ceiling was removed from its original location in the 1920s and spent decades in storage.  Doris Duke, a devotee of Islamic art and artifacts, purchased the ceiling in 1976 and installed it in her Hawaiian home in 1979, mislabeling it the Turkish Room. By 2009, the ceiling colors were dull and the adjami was deteriorated.

The author and her colleague performed conservation treatments during their summer workshop while students in the Winterthur/University of Delaware Program in Art Conservation.  While Travers breezed through her discussion of the treatments, which included injection adhesives and brush-applied consolidants, the real subject of her talk was the analysis of 50 finish samples from the ceiling.  She and her colleagues at Winterthur/University of Delaware tested the samples using eight different analytical techniques, including cross-section analysis, fluorochrome staining, PLM, XRF, SEM-EDS, FTIR, Raman and GC-MS.  The author described in detail her findings, particularly the blue, pink and green layers, as well as the varnish and tinted glaze layers.

While the author’s presentation was packed with information, she presented it in a clear and well organized manner.  She distilled a large amount of complex information into an easily understood whole.  This was my favorite talk of the ASG session, which was strong on its own. (Though perhaps I am biased, as I also perform paint investigations.)  I only wish that the author had had a full hour so that she could explain her subject in greater detail.  I would encourage the author to publish her findings.

39th Annual Meeting – Architecture Session, June 3, “Conservation of Dalle de Verre at the New York Hall of Science” by Laura Buchner and Chris Gembinski, Building Conservation Associates, Inc.

Laura Buchner and Chris Gembinski gave a fascinating presentation on the conservation of dalle de verre glass panels at the New York Hall of Science, a building erected for the 1964 World’s Fair.  Unlike many buildings erected for world’s fairs, the New York Hall of Science was always meant to be a permanent structure.  The Great Hall is a 90-feet high ribbon-like structure of dalle de verre glass panels.  The exhibition during the 1964 World’s Fair, “Rendezvous in Space”, made use of the deep cobalt blue dalles, highlighted by bits of ruby, green and gold, which give the interior the appearance of stepping into the cosmos.

The authors presented a brief description of how dalle de verre panels were made, both for this building and for typical buildings of the era.  According to the authors, 1964 was a transition period when Willet Studios, a manufacturer of dalle de verre panels, began switching from the poured concrete panels used at the Great Hall, to an epoxy matrix.

In 2005, BCA began restoring the Great Hall.  The goals of the project were to preserve the “experience of the building” and to address most of the deterioration and moisture-infiltration issues related to the building, but it was acknowledged by all parties involved that it would be impossible to cure all of the moisture-related problems due to the nature of original construction materials.  The authors explained how they treated the typical conditions–cracks, erosion of the matrix, spalls of the concrete matrix, cracked glass, biological growth, and exposed reinforcement mesh.  They replaced several panels with new dalle de verre set in an epoxy matrix, and rearranged some existing panels to minimize differences in light transmission between new and old units.  They repaired cracks by injection and surface-application methods, and used a consolidant and water-repellant to reduce further deterioration of the panels.  They also used a migrating corrosion inhibitor to reduce corrosion of rebar in the concrete grid.

The presentation was clear, informative, and well organized, and the conservation work looks expertly performed.  I enjoyed learning about dalle de verre, as I was not familiar with it prior to the talk.  I especially appreciated the authors’ willingness to share their experience using specific products, and the steps they took to maximize the efficacy of these products.

39th Annual Meeting – Architecture Student Session, 6/2/2011, 9:40AM-10:40AM

Following my own presentation in this session, I had the privilege of listening to my colleagues at Columbia University and the University of Texas-Austin discuss their research on architectural conservation material issues.

Sarah Sher (Columbia) exposed the design theory behind soiling on Marcel Breuer’s buildings through conducting an elaborate study of his personal writings and lectures.  She challenged conservators that approach Breuer’s structures to view the soiling as significant to its overall design aesthetic, because it was intentional.  For Breuer, reinforced concrete was the ideal material- requiring little to no cleaning (as opposed to its glass/steel counterpart), and that soiling in fact enhanced the aesthetic of the architecture “to aid in the process of aging.”  In the section of her presentation entitled “Designing the Aging Process,” Sher focused her discussion on Breuer’s Cleveland Trust tower.  Breuer anticipated heavy soiling on the structure, quoting the effects of polluted Cleveland air.  He designed for this effect, which he believed allowed shadowing and depth of the surface.  Sher ended her talk with Riegl’s conception of age value, and the questions that modernist pose for conservation interventions.  With a fascinating talk, Sher introduced research into a field that will need to be expanded and better understood as we are increasingly working on modernist and Brutalist structures.

Sarah Caitlin von Hedemann (Columbia) presented her thesis research on current cleaning formulations for removing biogrowth on stone, utilizing a newly manufactured Prestor gel.  She utilized laboratory testing, as well as field tests on sites around the city of New York, including 1- Wallace limestone (facade of the Metropolitan Museum of Art), 2- Indiana limestone (exterior of The Cloisters museum), 3- Texas limestone (Bronx Victory Memorial), 4-Tuckahoe marble ( Lagrange Terrace, Delbarton School), and 5- Carrara marble (Portrait Bust, Delbarton School) –if I mislabeled or misunderstood any of these stone types, please comment to correct me!  Utilizing analytical tests ranging from XRD, SEM-EDS, FTIR and GC-MS, she tested the products’ effectiveness and the presence of residues left by the cleaners.  von Hedemann concluded with her recommendations:  Prestor gel should be used for less porous stone, as it had atendency remove porous stone surfaces, CB-4 requires more research but was overall ineffective and left larger residues, BioKlean was successful but this might be due to its 2-step process and it is considered very agressive and alkaline, and D-2 and BioWash had average cleaning capability.

Payal Vora (UT-Austin) studied as a Materials Science engineer in her undergraduate education, and became interested in preservation efforts following natural disasters.  Her thesis is an extension of this interest, as she conducted a study of masonry cleaners for Fort Livingston, LA following the 2010 Gulf coast oil spill.  The fort, located on Grand Terre island is the only occupied barrier island in Louisiana, and has been greatly affected by the spill due to erosion issues that allow parts of the fort to remain underwater.  The unprecedented contamination of the spill, required a technical study to guide conservation efforts, and this was spear-headed by NCPTT and UT’s Architectural Conservation Laboratory.  Unable to remove original material from the fort, NCPTT provided contemporaneous brick (from a demolished early 1900s home) as samples for Vora’s study.  Developing her experimental design,Vora prepared her samples according to ASTM C-67-09, she developed a method for soiling the samples, and conducted artificial weathering with an Atlas C-4000 Xenon Arc Weather-oMeter on the brick Q-series.  On the U-Series, samples were unweathered, but placed in an oven for 8-10 hours to ensure samples were dry prior to cleaning.  Cleaners were chosen from the National Remediation Plan’s list of approved cleaners for the Gulf Coast spill- the 6 final choices were Petro-Clean, Cytosol, SC-1000, Gold Crew, De-Solv-It Industrial Form and De-Solv-It APC.  Cleaning was evaluated using telecolorimetry and a visual inspection survey.  Responding to a national crisis, the project represents an important effort in disaster relief for historic structures.

It was a pleasure to hear about the incredible work being done by emerging professionals in this field!