Volume 16, Number 1, Jan. 1994, pp.3-7
The 1993 WAAC Annual Meeting was held 25 October at the Marconi Conference Center in Marshall, California. The papers from the meeting are listed below along with summaries prepared by the speakers.
Vinod Daniel1, Gordon Hanlon2, Shin Maekawa1, Steve Colton3 and Don Menveg31 The Getty Conservation Institute
The Getty Conservation Institute (GCI) and the J. Paul Getty Museum have been evaluating the feasibility of eradicating museum insect pests by placing an infested object in an atmosphere devoid of oxygen for an extended period. The advantages of this method are that there are no damaging effects to objects and it is safe for both the environment and the operator.
This presentation will illustrate the use of a nitrogen atmosphere to treat the multi-media sculpture "The Back Seat Dodge 38" by Edward Kienholz. Because the object, from the permanent collection of Los Angeles County Museum of Art, contains organic materials and metals which may react adversely with conventional fumigants, the non-toxic method was clearly the only viable procedure. Examination of larvae found in the sculpture showed the infestation to be due to webbing clothes moths. From the GCI sponsored research at the University of California, Riverside we know that all life stages of this pest are killed when kept at a nitrogen atmosphere (less than 0.1% oxygen) for a maximum of 96 hours.
To enclose this large sculpture (66 x 240 x 144 inches) we tailor made a close fitting plastic bag, which was made from a commercially available oxygen barrier plastic sheet called Aclar (TM). By heat sealing lengths of this plastic sheet we made a one-bag unit to enclose the car. Pure nitrogen gas, conditioned at 50% relative humidity (corresponding to the ambient conditions of the gallery) was passed into the bag containing "The Back Seat Dodge 38" and out an exit duct at a high flow rate until the oxygen concentration decreased to less than 0.1%. Then we reduced the flow of nitrogen, maintaining the low oxygen level for 8 days.
The precise oxygen content, relative humidity, and temperature in the bag were continuously monitored throughout the treatment. After the treatment, we found dead adult moths and larvae on the floor inside the Kienholz sculpture. We will continue to monitor the object for the effectiveness of the treatment.
Sources of materials and supplies:
Circus posters revolutionized 19th century American advertising and spurred the development of commercial printing in the United States. Originally produced as "disposable" objects, literally for pennies, circus posters nonetheless remain some of the finest examples of 19th and 20th century printed artwork, utilizing a wide variety of printing methods, media and photography. In the last decade, the scarcity of early posters and the soaring market values of circus posters in general have caused art museums as well as history museums, many of which have significant collections of these artifacts, to reexamine their historical and artistic significance.
An understanding of the history, original production and use of circus posters is essential for their preservation, including designing conservation treatments which will preserve their artistic quality as well as protect important historical information which can easily be altered or lost during conservation treatments. This paper will examine a number of ethical issues regarding the conservation treatment of circus posters, and will relate some practical experiences regarding such treatments.
The full text of this presentation is published in this issue of WAAC Newsletter.
Mural painting can truly be said to date back to the earliest stages of mankind. Despite the history and continued importance of mural art there has been little direct scientific research to support the activities of artists or to enhance the aesthetic and physical conservation of their works.
The most active community of muralists in the U.S. exists in Southern California. Los Angeles County has over 1000 extant murals and a number of active programs for the production of new works. These works represent a vital and essential connection with the tradition of mural painting and the contemporary imperatives of social identification and representation. The City of L.A. and the Social and Public Art Resource Center of Venice, CA have embarked on a program to inventory the Los Angeles murals and to properly establish their condition. This is the first step in determining strategies for conservation interventions. Perhaps, more importantly, the conservation segment of the database will be the first comprehensive research tool that will be used to examine wall preparation technologies, siting and environmental factors, painting materials, graffiti interventions and other variables that affect the longevity of monumental works of art.
This talk will outline the type of data being collected and the interesting and sometimes conflicting results that can be obtained by quasi-objective study of the hard data collected.
Alfred Lucas was the first Director of the British Government Analytical Laboratories in Egypt during the early 20th century. Subsequent to his retirement from the Public Service in 1923, Lucas was appointed consulting chemist to the Cairo Museum where he became intimately involved in the development and application of new chemical treatment methods for the preservation of Egyptian antiquities. Though probably best known for his book Ancient Egyptian Materials and Industries, Lucas published over fifty books and papers on the technology and conservation of antiquities.
A chemist by profession, Lucas was one of the first British Egypgyptologists to adopt a rigorous, scientific approach to the treatment of museum artifacts. He was responsible for many advances in the field of archaeological conservation, and it was due to his singular efforts that many of the antiquities excavated from the Tomb of Tutankhamen by Howard Carter survive to this day.
A brief biographical sketch of Alfred Lucas will be presented as well as a detailed discussion of many of his most important scientific achievements. Particular emphasis will be placed on the impact which his work had upon the development of archaeological conservation in Egypt and abroad.
Abstract: The problems of flake loss and deterioration of the paint layer in medieval manuscript illumination has inspired a variety of remedies over the ages. Repainting areas of an illumination or replacing whole miniatures was an accepted practice used by medieval illuminators as well as nineteenth-century restorers to compensate for losses in medieval manuscripts. Such historical examples provide a dramatic contrast to current conservation ethics and practices of 1) consolidating losses in the paint layer and 2) infilling and reconstructing losses in the support. Consolidants used in manuscripts conservation will be discussed in relation to the painting materials used by the medieval illuminator. The appropriateness of a consolidants surface appearance, adhesive strength, working characteristics, and its effect upon manuscript pigments, colorants, and media will be discussed. The treatment of manuscript leaves in the Getty collection will provide examples of a range of parchment repair techniques as well. See also an expanded summary with bibliography later in this issue.
Abstract: The sculpture of St. Gines de la Jara in the collection of the Getty Museum is an outstanding example of the Spanish technique of estofado. Although the life-size figure retains most of the 17th century polychromy, a large loss to the sleeve presented a dilemma. In previous restoration treatments the problem of compensation had been addressed by attempting to simulate the effect of estofado; the results were visually disturbing and judged to be unsuccessful. During the recent re-treatment, the materials and layering of the polychromy were analyzed, the structure was examined with x-radiographs, and the intricate patterns of the decorative layer were transferred to mylar and studied. It was decided that compensation for all losses, including the missing portion of the sleeve, would be carried out without duplicating the original technique or using gold leaf.
Once the domain of computer scientists and defense researchers, the Internet, a global computer network connecting many thousands of machines worldwide, has in recent year become an indispensable resource for people in the Humanities and Social Sciences. The influx of this new population has helped to bring to the Net a wealth of new services and information sources, many of them of great significance to conservators. Todays tour will explore some of the new exciting tools available on the Net, including Gopher, Wide Area Information Servers (WAIS), and World Wide Web, as well as the well established services such as FTP (File transfer, telnet [remote login], email, etc.). Highlights will include the Conservation DistList, an online forum for conservation professionals, and Conservation OnLine, a full text conservation database.
Reverse paintings on glass are unique because glass acts both as the support and the varnish. Glass is an inappropriate substrate for oil paint as the two materials have very different rheological properties. As a result, hinterglasmalerei have had a long history of detachment, leading to disfiguring bubbles, color shifts due to change in refractive index and eventual paint loss.
This presentation describes the treatment of a very large hinterglasmalerei - 6' x 3' and weighing over 100 pounds - which had over 30% of its area detached from the glass support. Most of the detachments were blind, with the paint film intact but separated from the glass. Many small chips of paint had fallen behind a pocket of detached paint. Treatment involved the selection of an appropriate adhesive with good flow properties and the correct refractive index. Adventures in chip retrieval and bubble hunting as well as interesting two-person inpainting method will be described.
Sources of materials and supplies:
Epotek 301: Epoxy Technology, Inc., 14 Fortune Drive, Billerica, MA 01821. Tel: (800) 227-2201.
Glenn Wharton and James Grant served as conservation consultants for the general contractor during the recent renovation of the Los Angeles Central Library. Individually, they also wrote specifications for conserving historic surfaces within the building, cataloged and crated the artifacts, and performed conservation treatments on the sculptural features of the building.
The Los Angeles Central Library re-opened to the public on October 3, 1993, seven years after the two destructive fires that forced the building to close. This presentation provided an overview of how conservation concerns were integrated into the complex renovation of the historic building.
The subcontractors who performed the work on the historic surfaces were committed to follow detailed specifications provided in the bid package. These specifications included pre- qualifying experience and required that the subcontractors abide by the Secretary of the Interiors Standards for Rehabilitation. Prior to any actual cleaning or restoration, the subcontractors performed tests and mock-ups, which were reviewed by the general contractor's conservators (Tutor Saliba Corporation). The tests and mock-ups were then demonstrated to the project architects (Hardy, Holzman, Pfeiffer Associates) and an inspector from the city of Los Angeles. Once the procedures were approved, the subcontractors provided the city with detailed submittals, specifying the exact methods and materials to be used during each step of the restoration process. The work of the subcontractors was reviewed periodically and given a formal inspection after completion. This formal process is cumbersome compared with the treatment proposals and reports provided by museum conservators. It is standard in the building industry, however, and served to maintain high standards of workmanship during this project, which involved many parties with opposing interests and often very little appreciation for maintaining the historic character of the building.
Abstract: Human exploitation of plant materials for food, medicine and items of material culture is the concern of ethnobotany. Aspects of ethnobotany provide useful information to conservators. The knowledge of what plant materials were used in making a cultural artifact and how they were processed can provide critical insights in the understanding of the structure of the object and its deterioration processes. Plant materials are also used to repair artifacts in indigenous and non-western societies. Little attention has been paid to these materials and their properties by conservation professionals except perhaps for the widespread adoption of Japanese paper and adhesives in conservation practice. This talk will present a brief overview of these issues, discuss the literature of the discipline and areas where research is needed as well as new trends in ethnobotanical research. Ethnobiology, the larger discipline that encompasses the use of plant and animal materials, will be described.
American artist Robert Motherwell (1915-1991) painted his Elegy #57 in 1957; he subsequently made significant design changes, using a paint which proved to be highly incompatible with the lower layer. The painting dates from a transitional period in the artist's work, between his early oils and his later acrylics. This presentation documents the most recent treatment of the severe interlayer cleavage that resulted from Motherwells choice of materials. The treatment, performed by paintings conservators at the San Francisco Museum of Modern Art (with visiting conservator Tony Rockwell) is the subject of an exhibition at the Museum this fall.
Laura Downey1, Irene Brückle2, F. Christopher Tahk21 WRPCL
This paper investigates technical aspects of stone lithography, including: a discussion of lithographic limestone; the chemistry involved in the preparation and printing of a lithostone; and preliminary research on the possible effects of lithographic printing on paper. Most lithostones come from the Solnhofen quarry in Bavaria. The chemistry of the process is complex, involving interactions of gum arabic, soaps and acid with the stone. Although no true platemark is formed on a lithograph during printing, the paper is compressed, which should be taken into consideration before conservation treatment is begun. This paper is the culmination of research undertaken by Laura Downey in her second year at the Art Conservation Department of the State University College at Buffalo.
A lengthy conservation project at the Fine Arts Museums of San Francisco has involved the treatment of a 15th century Spanish polychromed wooden ceiling from Torrijos, Spain. The ceiling consists of eight octagonal dome panels, a center cartouche, and four polychromed wall and corner panels. Elisabeth Cornu has coordinated the conservation project which, due to the size of the panels, is carried out at the Oakland Museum Conservation Center facility. The project involves considerable structural repairs, replacement of gilded elements, removal of two campaigns of overpaint on the wall panels, recovery of original polychrome Mudejar patterns, and, finally, aesthetic integration of large areas of lost polychromy. Conservator Alejandro Reyes-Vizzuett is assisting with structural conservation work to prepare the panels for rehanging. Conservator Krasimir Gatev has assisted with the stabilization of the polychromy of the wall panels, the removal of two layers of recent tempera overpaint, and the recovery of the original polychromy.
We are pleased to present our newly found methods of restoring large areas of gold leaf within a low-cost budget; and of time- consuming overpaint removal and integration of original polychromy. This work is accomplished with a team of consulting conservators, aided by a dedicated group of interns.
The destructive action of soluble salts in stone objects is well- known, and there are a variety of techniques available for salt extraction: removal of dry salt, immersion and bathing in water, membrane electrodialysis, suction and poulticing. The aim of wet desalination methods is the removal of salts by dissolution in water. In some cases, the salts themselves may be a critical cementing agent in surface layers of highly fragile, deteriorating stone and therefore exposure to water may result in appreciable stone loss.
The first step in a desalination treatment of flaking and crumbling stone (following analysis of materials and assessment of the extent of deterioration) is treatment with a preconsolidant. Requirements for a preconsolidant include imparting sufficient strength to the stone to withstand a desalination procedure (and possibly a cleaning procedure) while allowing both the successful removal of salts by dissolution and further consolidation treatment.
Preconsolidant materials mentioned in the conservation literature through the years include wax and paraffin, acrylic and poly (vinyl acetate) resins and emulsions, polyvinyl alcohols, epoxies and salines. The aim of this study is to conduct a comparative analysis of preconsolidants for weak, salt-laden stone in order to identify materials and application procedures suitable for specific types of stone substrates and soluble salt compositions.
Initial data on the removal of sodium sulfate from laboratory- degraded sandstone treated with solutions of commercially available acrylic and epoxy resins, and ethyl polysilicate are reported. Of particular interest is the kinetics of salt removal by immersion in deionized water; and the effect of consolidant concentration on salt extraction rate. If full consideration can be achieved with a high concentration of a material that still allows salt extraction, although at a lower rate, the need for a two-step consolidation treatment might not be required. The rationale for future testing of different types of stone substrates, salt compositions, preconsolidants and desalination procedures is also discussed.
In the Southwestern United States, adobe buildings comprise a significant proportion of our architectural heritagtage. The recognition of this fact has led to an increasing interest in devising better ways to preserve historical adobe buildings. Some methods have been developed for use on archaeological sites and are not suitable for buildings that are in use. Additionally, some methods are not cost effective in that they use materials that are beyond the means of many local groups working on restoration projects. The current program is a demonstration project to investigate the possibility of adapting traditional methods and additives used in making adobe plasters to modern preservation methods. Ten historic plasters, taken primarily from churches in Northern New Mexico, are being extensively examined in this study. Initially each of the plasters is being analyzed using modern materials characterization techniques to identify what materials result in durable plasters, i.e. plasters that last for at least five years with minimum maintenance. The laboratory studies are being accompanied by field studies that include oral history interviews about the making of the sample plasters and also working with plaster makers to learn how they manipulate their mixes. The results to date will be presented and discussed.
Following the 1991 installation and opening of the new downtown building, S.A.M.s attention is now turned to the renovation and reinstallation of the 13,000 s.f. galleries at the original 1932 Volunteer Park location.
Opening in the summer of 1994 as the Seattle Asian Art Museum, 600-900 objects from the permanent collection will be installed.
New mount systems, with conservation and seismic concerns being addressed were used throughout the downtown facility, and now production of the second generation of mounts for Volunteer Park is under way. This second generation sees again new materials, tools, and techniques to continue the development of mounting systems for exhibits and storage.
As many museums with Native American collections evolve toward a collaborative, inclusive philosophy and practice, conservators are charged with the responsibility of integrating these new principles into their own methodologies. At the Museum of Indian Arts and Culture in Santa Fe, a major exhibit project is under way which presents conservators with the opportunity to reassess past practices and move toward a more appropriate approach. In planning conservation for this exhibit, a survey of objects is necessary to project treatment hours. However, in keeping with the exhibit philosophy, even basic treatment proposals cannot be made without crucial contextual and cultural information, as well as the perspectives of Native American curators and advisors. Therefore, the survey methodology for this exhibit is designed in such a way as to incorporate not only an assessment of physical condition, but also other information and perspectives needed to make treatment decisions.
Timestamp: Thursday, 11-Dec-2008 13:02:32 PST
Retrieved: Wednesday, 26-Sep-2018 02:49:46 GMT