2.16 Consolidation of Ethnographic Objects
 

The Getty Conservation Institute

Eric Hansen
Eilene Sadoff
Rosa Lowenger
Period of Activity: 1988-1990

Project Abstract
The purpose of this investigation was to review with conservators methods and materials used in the consolidation of ethnographic surfaces and surfaces with high pigment volume concentrations (PVC), and to investigate alternate approaches to consolidation.

Primary Publications
Hansen, E., E. T. Sadoff, and R. Lowinger, "A Review of Problems Encountered in the Consolidation of Paint on Ethnographic Wood Objects and Potential Remedies," Proceedings of the ICOM 9th Triennial Meeting, Dresden, Vol. 1, August 1990, pp. 163-168.

ABSTRACT-Problems encountered in the consolidation of paint on ethnographic wood objectsare reviewed, based upon the literature and surveys of North American ethnographic conservators. Significant consolidation may require a large quantity of resin, which affects the appearance of the paint. Changes in appearance may be minimized by selecting either particular application procedures or resins that are effective in lower concentrations. The solution properties (volatility, viscosity, surface tension) may be as important as, or more important than, the physical properties of the dried resin. As removal of the resin used to consolidate a fragile deteriorated paint is unlikely, the aging characteristics are of primary importance in the choice of resins. Insoluble thermosetting resins (diisocyanates, epoxies) are considered due to their high strength in low concentrations, compared to thermoplastic resins.

Hansen, E., and E. Sadoff "The Use of Facsimiles in Research on the Conservation of Painted Ethnographic Wood Objects," Paper presented at the WAAC, Honolulu, Hawaii, October 1989.

ABSTRACT-Facsimiles produced in a laboratory can simulate, to certain degrees, problematic painted wood surfaces of ethnographic objects. Wood objects painted with clays or ochres bound with an insufficient amount of binder or an ineffective binder often have surfaces of loose, flaking, or powdering paint. Facsimiles are being used at GCI to research new materials and methods for the conservation of these objects, and also to determine the causes of deterioration. The paint manufacturing technologies of cultures (Oceanic and African) whose objects often exhibit problems with the painted surfaces are being considered in the production of these facsimiles. The cracking patterns and the flake morphology of the facsimiles are under study to explore a possible relationship with the pigment and binder type, the method of paint application, movement of the wood substrate (resulting from fluctuations in relative humidity), or any possible combination of these three. These patterns could then provide visual clues to the underlying causes of deterioration. Strategies for consolidating or readhering porous, flaking paint without affecting a matte appearance are also presented.

Hansen, E., and R. Lowinger, "Materials and Methods for Consolidating Paint on Ethnographic Objects," WAAC 1989 Conference, Catalina Island, California, October 15-17.

ABSTRACT-This paper presents materials and methods for consolidating paint typical of that found on ethnographic objects. Sources of information include surveys of ethnographic conservators in the United States, results of workshops conducted with the participants of the Getty Conservation Institute (GCI) Training Course on the Consolidation of Painted Ethnographic Objects (Conservation at the Getty) Institute (GCI), questionnaires sent to selected ethnographic conservators in the United States, Canada, and Australia, research conducted in the Scientific Program of the GCI, and consultation with scientists active in the fields of conservation or coatings. A major problem encountered in the consolidation of paint on ethnographic objects is the consolidation of flaking porous or crumbling paint, powdering surfaces or multiple layers of paint without altering the appearance. The following methods are reviewed in respect to specific problems with a painted surface: different application procedures for solutions, reforming of polymer films by heat or solvent, use of matting agents, high-viscosity solutions, consolidation and adherence of paint in separate steps, saturation of porous flakes with hydrophobic solvents and adhering with aqueous emulsions, solutions with low-volatility solvents, saturation of the working atmosphere with solvent fumes, use of surfactants, prewetting of surfaces, multiple applications of dilute solutions, relaxation of brittle surfaces with high humidity, application of solutions through a permeable facing, adjusting solvent polarity, subsequent surface matting, and methods for consolidation of friable, flaking surfaces without forming a coherent film.

Hansen, E., and R. Lowinger, "Investigations into Techniques for the Consolidation of High Pigment Volume Concentration Paint at the Getty Conservation Institute," WAAC Newsletter, Vol. 12, Nš 3, September 1990, pp. 13-16.

ABSTRACT-The problems encountered in the consolidation of painted ethnographic objects were reviewed in preparation for an advanced training course for ethnographic conservators conducted at the Getty Conservation Institute, June 11 to June 29, 1990, "The Consolidation of Painted Ethnographic Objects." The course was developed under the direction of Sue Walston, coordinator for the ICOM Ethnographic Objects Working Group and previously Head of Materials Conservation at the Australian Museum. This article describes the specific problems encountered.

Hansen, E. F., E. T. Sadoff, and R. Lowinger, "A Review of Problems Encountered in the Consolidation of Paint on Ethnographic Wood Objects and Potential Remedies," Preprints, ICOM 9th Triennial Meeting, Dresden, Vol. 1, August 26-31, 1990, pp. 163-168.

ABSTRACT-Problems encountered in the consolidation of paint on ethnographic wood objects are reviewed, based upon the literature and surveys of North American ethnographic conservators. Significant consolidation may require a large quantity of resin which will affect the appearance of the paint. Changes in appearance may be minimized by selecting either particular application procedures or resins that are effective in lower concentrations. The solution properties (volatility, viscosity, surface tension) may be as important as, or more important than, the physical properties of the dried resin. As removal of a resin used to consolidate a fragile deteriorated paint is unlikely, the aging characteristics are of primary importance in the choice of a resin. Insoluble thermosetting resins (diisocyanates, epoxies) are considered due to their high strength in low concentrations, compared to thermoplastic resins.

Hansen, E., R. Lowinger, and E. Sadoff, "Consolidation of Objects in a Solvent Vapor Saturated Atmosphere: A New Technique for Minimizing Changes in Appearance," Paper presented to the Objects Specialty Group, American Institute for Conservation Annual Meeting, Richmond, Virginia, 1990.

ABSTRACT-Changes in appearance of a matte powdering clay or ochre paint which results from consolidation with a solution of a thermoplastic resin include darkening, discoloration, or increased glass. These may be minimized by applying the consolidant in an atmosphere saturated with vapors of the solvent used to dissolve the resin. In addition to maintaining the original appearance of the object, other benefits include the absence of a tide line and greater penetration of the solution for improved adhesion of the consolidated paint to the substrate. The low cost of the plastic glove bag used to maintain the vapor saturated atmosphere and the portability of the system make it easy and inexpensive to use.

At the present time, we are limiting the use of this technique to objects, or areas of objects, which are not sensitive to solvent vapors. Five percent solutions in acetone of Acryloid B72 and poly(vinyl acetates) yield results as effective as those found with diethylbenzene, without the problems associated with DEB. These include long-term solvent retention and noxious properties, among others. We believe this technique is considerably promising for two areas of materials: clay, ochre, ceramic, terracotta, brick, or other powdering and/or crumbling inorganic surfaces with little potential for solvent interaction; and flexible objects such as baskets, painted wood, etc., where a more flexible polymer than B72 is desired. The theoretical basis for the observed phenomena is presented along with the results of consolidating ochre or clay with B72 or PVAC in solutions of acetone, toluene, and ethanol.

Hansen, E., R. Lowinger, and E. Sadoff, "Consolidation of Porous Paint in a Vapor Saturated Atmosphere: A Technique for Minimizing Changes in the Appearance of Matte, Powdering Surfaces," Journal of the American Institute for Conservation, Vol. 32, 1993, pp. 1-14.

ABSTRACT-A technique is described for consolidating matte, low-gloss, powdery surfaces without darkening the colors. When resins are applied for consolidation of such matte surfaces, darkening of the colors may occur because of an increase in the gloss of the surface, due to the formation of a film over the surface to be protected. The technique outlined involves the application of a stable thermoplastic resin solution in an atmosphere containing a very high concentration of the solvent used to dissolve the resin, thus slowing solvent evaporation and allowing the resin to penetrate into and around the exposed pigment particles. In addition to retaining the matte appearance of the object, "tide lines" are prevented and adhesion of the pigment may be improved.

Hansen, E. F., P. Volent, M. H. Bishop, and R. Lowinger, "The Consolidation of Matte, Porous Paint: Examples from Ethnographic Objects and Contemporary Works of Art," AIC Paintings Specialty Group Postprints, Presented at the 21st Annual Meeting of the American Institute for Conservation of Historic and Artistic Works, Denver, Colorado, June 5, 1993, pp. 67-71.

ABSTRACT-Matte, porous paint, highly friable and difficult to consolidate without darkening and discoloring, is found in a wide range of objects. Some physical and optical properties of this type of paint, as a result of high pigment volume concentration and diffuse surface reflectance, are presented with a stress on ramifications for treatment parameters. The problems encountered in transferring the results of controlled laboratory studies into effective conservation treatment procedures are also discussed in reference to painted ethnographic wood objects and contemporary works of art on paper (with a cautionary note on undesirable solvent sensitivity).

Hansen, E. F., and M. H. Bishop, "An Interdisciplinary Bibliographic Approach to a Complex Conservation Problem: The Consolidation of Matte Paint," Working Group 4, Preprints, Vol. 1, ICOM Committee for Conservation 10th Triennial Meeting, Washington, D. C., August 22-27, 1993, pp. 189-194.

ABSTRACT-Describes a literature survey, occasioned by a research project into the problems of consolidating matte, friable paint, with an emphasis on ethnographic objects. Available bibliographies and databases, such as BCIN, CAS, and Rapra, provided few references.

Although few references were initially located, isolating the problem's physical nature and understanding its interdisciplinary aspects aided in identifying and compiling a wide variety of literature of direct relevance to the problem and useful to the conservator in designing treatment strategies. Annotated references to this literature have been gathered into a topical supplement to Art and Archaeology Technical Abstracts (AATA), to be published autumn 1993. The organization, sources, and unique aspects of this bibliography are described in this paper, as is the research methodology used to assemble the references.

Hansen, E., and M. Bishop, "The Conservation of Painted Archaeological and Ethnographic Objects," The Getty Conservation Institute Newsletter, Winter 1993, Vol 8, Nš 1, p. 14.

ABSTRACT-Discusses the relatively undeveloped state of conservation for archaeological and ethnographic objects and the inherent fragility of these objects. Continues to describe the course on the "Consolidation of Painted Ethnographic Objects" given by the Training Program of the GCI and the research and publications that resulted from the course. Gives a brief description of the special supplement to AATA, Matte Paint: Its History and Technology, Analysis, Properties, Deterioration and Treatment, with Special Emphasis on Ethnographic Objects, as an attempt to begin to address specific issues in this important area.

Hansen, E. F., and P. Volent, "Technical Note on Solvent Sensitivity Testing of Objects for Treatment in a Vapor-Saturated Atmosphere" Journal of the American Institute for Conservation, 1994, 33:315-316.

ABSTRACT-None available.

Hansen, E. F., S. Walston and M. H. Bishop, "Matte Paint: Its Technology and History, Analysis, Properties, Deterioration and Treatment with Special Emphasis on Ethnographic Objects; a Critical, Annotated Supplemental Bibliography to Art and Archaeology Technical Abstracts" (Los Angeles, CA: The Getty Conservation Institute and the International Institute for Conservation) 1994.

ABSTRACT-None available.

Hansen, E. F. and M. H. Bishop, "Factors Affecting the Retreatment of Previously Consolidated Matte Painted Wooden Objects" in Painted Wood: History and Conservation (Preprints of the November, 1994 Symposium at Colonial Williamsburg) in press.

ABSTRACT-None available.

Matte Paint: Its History and Technology, Analysis, Properties, Deterioration, and Treatment, with Special Emphasis on Ethnographic Objects, Hansen, E. F., S. Walston, and M. H. Bishop (eds.), In Art and Archaeology Technical Abstracts, The (Conservation at the Getty) Institute, Supplement 30, Nš 3, August, 1994.

ABSTRACT-Although the primary emphasis in this bibliography, a supplement to Art and Archaeology Technical Abstracts, is on ethnographic objects, it also includes information on the deterioration and conservation of matte paint on immovable objects, including painted walls and architectural ornamentation, and on the conservation of unpainted matte areas, such as painted wall and architectural ornamentation. The occurrence and treatment of architectural decoration of clay or stucco in prehistoric Mesoamerica are also discussed.

This topical bibliography contains more than 1,500 abstracts of periodical, monographic, and unpublished literature from the fields of anthropology, conservation, ethnobotany, art history, and coatings science. In addition, there are a number of abstracts of audiovisual sources, particularly historic films from early anthropological studies.