Frank G. Matero

CLEANING, IRON STAIN REMOVAL, AND SURFACE REPAIR OF ARCHITECTURAL MARBLE AND CRYSTALLINE LIMESTONE: THE METROPOLITAN CLUB

Abstract The Metropolitan Club, designed and built in New York City by McKim, Mead, and White in the 1890s, has particularly extravagant exterior stonework. However, as a result of the type of stone selected, natural weathering, and improper maintenance over time, the stonework had become severely discolored and eroded by 1989. The authors first characterize the stones used and describe the types of damage found, all identified with various analytical techniques, including thin-section petrography, scanning electron microscopy, and energy-dispersivex-ray spectroscopy. The authors then discuss the treatments carried out on the stonework, including metallic stain removal, consolidation, and mechanical repairs.

THE CONSERVATION OF IMMOVABLE CULTURAL PROPERTY: ETHICAL AND PRACTICAL DILEMMAS

AbstractThe conservation of immovable cultural property—outdoor monuments, buildings, archaeological sites, and landscapes—is a relatively recent profession, yet one that has grown out of earlier 19th-century restoration theories. Although part of the broader conservation context, architectural conservation presents unique problems due to the issues of context, immobility, size, scale, and complexity of use and materials. These issues are examined with respect to established standards for the examination, documentation, and treatment of traditional historic and artistic works.

Managing Change: The Role of Documentation and Condition Survey at Mesaverde National Park

Abstract The approximately 600 cliff dwellings in Mesa Verde National Park in Colorado represent the apex of architectural sophistication of the Northern San Juan Ancestral Puebloan culture. The cliff dwellings, the final product of 600 years of cultural development on the Mesa Verde, were built between A.D. 1200 and 1300, and were abandoned shortly thereafter. The spectacular setting and the well-preserved state of these masonry structures and their surface finishes resulted in Mesa Verdes being the first nomination by the U.S. government to the World Cultural Heritage Sites List. Moreover, descendants of these ancient peoples, the Pueblo Indians of Arizona and New Mexico, continue to venerate these sites, representing a cultural continuity unique for North America. Excavation and preservation have been continuous since Mesa Verde became one of the first national parks in 1906. The structures interpreted to the public have been preserved over the years with a minimum of repair and replacement, resulting in a cultural resource of great integrity and authenticity. A phased conservation program to develop coordinated methods for the survey, analysis, stabilization, and interpretation of the masonry and prehistoric surface finishes in the alcovate (cliff-dwelling) sites of Mesa Verde National Park has been in progress since 1994 by the Architectural Conservation Laboratory of the University of Pennsylvania. The program has included a comprehensive method of study, including archival research, technical analysis, and characterization of the architectural materials; detailed field and digital recording of existing conditions, including environmental monitoring; and the design, testing, and execution of a treatment and protection program specifically focused on the in situ stabilization of plain and painted architectural surface finishes. Though case-study oriented, this article addresses in detail the theoretical and technical aspects of condition survey and recording as an important vehicle for material and site diagnostics, which must precede remedial and preventive interventions. Detailed information is provided on the use of current digital technology for condition survey.

Design and evaluation of hydraulic lime grouts for the reattachment of lime plasters on earthen walls

AbstractA laboratory and field testing programme for the formulation and evaluation of hydraulic grouts was developed for the reattachment of lime plasters on earthen (adobe) walls. Formulations utilizing kaolin, hydraulic lime, ceramic microspheres, and fine silica sand, with and without the addition of an acrylic emulsion, were prepared and evaluated in a three-stage testing programme. Standard tests were employed to measure injectability, viscosity, set time, shrinkage, weight, splitting/tensile strength, water vapour transmission rate, and adhesive bond strength. Grout microstructure was comparatively examined using scanning electron microscopy. Of the 18 grout formulations tested, only one mixture composed of (parts by weight) 1 part microspheres, 1 part sand, 2 parts hydraulic lime, 10% part acrylic emulsion was found to meet all the essential performance criteria established.

Loss, Compensation and Authenticity in Architectural Conservation

Abstract Loss and compensation have been central issues in the conservation of art and architecture at least since the sixteenth century as described by Vasari.1 In modern conservation practice, the term ‘compensation’ is now used to include all aspects of intervention designed to address visual and structural reintegration resulting from material loss.2 They are inextricably tied to conservations primary objective, the protection of cultural resources from damage and depletion. Their consideration reveals much about past and present notions of cultural heritage including its meaning and significance across time, and the interventions that have been employed for its preservation and presentation. Discussions of material loss and its remedy, compensation, ultimately confront the larger questions concerning all artistic and historic works: authenticity, artistic intent, and value. For the student and experienced professional alike, issues of material loss and degradation and the oft-stated requirement of structural and visual reintegration can be among the most difficult problems encountered in conservation regardless of whether the work is a painting, sculpture, tapestry, or building. In considering such fundamental issues as loss and compensation, we bring conservation as a discipline, increasingly defined and separated by its specializations, back together to consider its essential and unifying issues and tenets.3

Lessons from the Great House: Condition and treatment history as prologue to site conservation and management at Casa Grande Ruins National Monument

AbstractAs the first federally designated and protected archaeological preserve in the United States (1889–92), the site of Casa Grande Ruins National Monument in Arizona, USA, provides an excellent opportunity to examine the effects of past site conservation and management policies. Renewed investigation and analysis of the caliche building material and wall conditions of the Casa Grande using new techniques of field, laboratory and digital recording have allowed a reassessment of the structure in an effort to explain recent phenomena of alteration and deterioration, and make recommendations for structural and surface monitoring and treatment. The focus on the development of a detailed condition survey of the earthen structure has also promoted the creation of a standard graphic lexicon of earthen building conditions for use at other sites.

Survey Methodology for the Preservation of Historic Burial Grounds and Cemeteries

An integrated program of digital surveying and mapping can provide a powerful database for the analysis, conservation, and management of historic burial grounds and cemeteries. Comments Reprinted from APT Bulletin, Volume 34, Issue 2/3, 2003, pages 37-45. We have contacted the publisher regarding the deposit of this paper in ScholarlyCommons@Penn. No response has been received. This journal article is available at ScholarlyCommons: http://repository.upenn.edu/hp_papers/5 Survey Methodology for the Preservation of Historic Burial Grounds and Cemeteries Frank G. Matero; Judy Peters APT Bulletin, Vol. 34, No. 2/3. (2003), pp. 37-45.

A programme for the conservation of architectural plasters in earthen ruins in the American Southwest: Fort Union National Monument, New Mexico, USA

AbstractPlasters constitute an important component of many ruined architectural and archaeological sites. Methods for their in situ conservation have lagged far behind the field treatment of other materials due to their ephemeral nature and the lack of programmatic laboratory and field research. A preservation strategy involving documentation, stabilization, interpretation and maintenance offers a methodological approach adaptable to most contexts. A pilot conservation programme is described for the stabilization and interpretation of the lime plasters within the nineteenth-century adobe ruins of Fort Union National Monument in New Mexico. Methods of documentation, emergency stabilization, injection hydraulic lime grouting and mortar repairs are described.

A Comparative Study of Ethyl-silicate–based Consolidants on Earthen Finishes

Abstract Comparative evaluation was performed on three commercially available ethyl silicates as possible consolidants for earthen finishes: uncatalyzed Silbond 40 in a 1:1 solution with ethanol, Conservare OH100, and Funcosil SAE 300E. Of particular interest was the compatibility of ethyl-silicate–based consolidation with water-based reattachment treatments. The testing program utilized facsimile coupons representing earthen finishes found at Mesa Verde National Park in Colorado and measured exposure to changing relative humidity, response to liquid water, surface cohesion, and effect on appearance. Samples were subjected to measurement with a linear variable differential transformer, environmental scanning electron microscopy, timelapse photomicrography, observation during wet-dry cycling, water drop absorption testing, colorimetry, and photographic recording. A comparison of the three ethyl-silicate–based consolidants clearly demonstrated that they can perform very differently on the same earthen substrate, and that careful selection should be made prior to use. Many questions remain regarding the influence of the finish composition, finish condition, and environmental conditions on the effectiveness of consolidation; further test development and testing are recommended.

Exploring conservation strategies for ancestral puebloan sites: Tsankawi, Bandelier National Monunlent, New Mexico

Abstract In the American Southwest, indigenous pueblo cultures are a vital part of the regions contemporary mosaic of ethnic diversity. This is especially evident through their long-standing relationship to the land and landscape as reflected in the continuity of place for all pueblo communities and the countless number of ancestral sites that figure prominently in contemporary beliefs and practices. Recently many such sites have gained federal recognition and legal protection as archaeological and traditional cultural sites, yet stabilization, protection, use and interpretation of these sites according to existing theories and models of conservation have proven difficult. Based on the recognition that such places remain critical to the continuing identity of Native peoples and that many of these sites are simultaneously visited and enjoyed by the public, their preservation and respectful management have become a relevant, timely and sometimes controversial issue. Beginning in 1997 the University of Pennsylvania, the National Park Service and San Ildefonso Pueblo inaugurated an integrated research and training programme focused on the conservation and management of Tsankawi (New Mexico), an ancestral puebloan mesa site of great cultural and archaeological significance. The project afforded a critical examination of the theoretical and ethical issues surrounding the preservation and management of ancestral archaeological sites and the technical methods required for their stabilization and interpretation as cultural landscapes. Professionals, students and pueblo affiliates engaged in documentation, condition survey and preservation treatments of the ancient tuff rock trails and pueblo structures. From this effort, a strategic conservation plan was developed and its initial implementation explored through an annual training programme involving pueblo and university interns as well as professional archaeologists and cultural resource managers.