Abstracts, WAG session,
The Use of Azeotropes in Treating the Elaborate
Polychromy of the Sleigh “The Turtle” (1832), in the Coach
Museum, Chateau of Versailles
Thoughts on Exhibition Solutions for Upholstery
An Investigation of Cleaning Methods for Untreated
An Approach to Compensating for the Structural
Failure of a Jean-Henri Riesener Bureau Plat
Packing a Collection: Furniture Packing, Transport
and Storage at the Museum of Fine Arts, Boston
The Use of Antibodies and Fluorescence Microscopy
for the Identification of Proteins in Artists' Materials
The Unveiling of "Old Smokey:" the
Treatment of a Mid-Nineteenth Century Concord Coach
The Conservation of the Pinzon Bar located
in Valdez, Alaska
Preserving the Big Stuff: What to do when
it won't fit in an exhibit case and it isn't quite architecture?
Technological Innovations in Woodworking Machinery
and Methods in Federal Boston
The Study and Treatment of an Important 1820's
Tortoiseshell and Imitation Tortoiseshell
The Use of Azeotropes in Treating the
Elaborate Polychromy of the Sleigh “The Turtle” (1832), in
the Coach Museum, Chateau of Versailles
This paper continues the discussion developed in an earlier paper (Augerson, 2000) on the use of azeotropic solvent mixtures in conservation treatments. After a brief description of the sleigh 'The Turtle', from the Royal Collection of Louis XV, analysis of its polychromy will be presented, including visible, fluorescence, FTIR and SEM-EDS analysis. The techniques for decorating and redecorating it during the 18th century are revealed. The treatment of this complex polychromy is discussed, and the usefulness of azeotropes in both consolidation and cleaning is emphasized.
Thoughts on Exhibition Solutions for Upholstery
Untreated wood is a material found in a wide variety of art objects in museum collections. In the context of this study, the word "untreated" signifies the absence of coatings such as paint, wax, varnish or any other protective coating on the surface of the wood. This paper examines a range of dry cleaning methods and materials already accepted by the conservation community as appropriate for cleaning paper, raw canvas and textiles, and will evaluate their ability to clean untreated wood. These tested methods employ the basic principle of erasers, namely using an absorbent, malleable material to capture and contain foreign matter, including general soiling and surface accretions, which then acts as a vehicle to transport the foreign matter away from the surface of the object.
Two main factors are considered to evaluate these cleaning methods for this application. First, there is potential for the wood to become physically abraded during the cleaning process. If the wood becomes burnished as a result of the mechanical action of cleaning, a change in the overall surface gloss, or sheen, may occur. Second, there is potential for cleaning product residue to be left embedded in the wood grain or surface cracks. This residue could potentially cause direct discoloration due to its presence, or stain and discolor the object as the trapped material ages and deteriorates over time. These two factors are evaluated using three analytical methods: spectrophotometry, visual microscopy and ultraviolet fluorescence.
The study involved the participation of conservators from the Museum of Modern Art. Each conservator cleaned samples of untreated Douglas fir plywood using the same dry cleaning techniques and materials. A baseline was created to eliminate the subjective and variable force that is applied during the cleaning process by individual conservators. This parameter was essential to define in order to make the results of this study useable.
The flat writing desk, or bureau plat, was a common furniture form in eighteenth century France. Examples are often compromised, as long structural members of the frieze must support gilt bronze mounts and complex extension writing and reading surfaces. Resulting loads can create sufficient stress that exceeds the proportional limits of the structural rails resulting in permanent deformation.
This paper will discuss the treatment of a bureau plat, circa 1785, attributed to ebeniste Jean-Henri Riesener, presently in the collection of the Baltimore Museum of Art. The neoclassical desk includes a hidden cantilevered extension table and articulated reading table. The weight of these components exacerbated the problems of the structural rails of the writing assembly to the point of complete failure. Due to the damage, the piece has not been exhibited.
The treatment of the structure included the insertion of a new internal metal armature fabricated of aviation grade steel. The logistics of the armature’s design, construction, and installation will be discussed. Other aspects of treatment such as compensation for sun bleached veneers and cleaning of gilt bronze mounts will be included.
The Museum of Fine Arts, Boston is in the process of emptying the east wing of the museum to allow for its demolition and the erection of a new wing to house the extensive collection of the Art of the Americas. As part of this process a large percentage of the museums American and European furniture collections needed to be moved off site and to be stored until the new wing is complete. Two different systems were jointly developed by the Conservation and Collections Management department of the museum and two art packing firms. For case pieces a palette system was designed where the furniture would be strapped into custom made enclosures that would stabilize the furniture during transportation. After unstrapping, the furniture would remain on its palette during storage and could then be restrapped for the return journey to the museum. For chairs and sofas a reusable crate system was developed and these pieces are uncrated and stored on open shelving.
This talk will illustrate the different systems which were developed and will discuss the design process and other factors which needed to be considered such as packing materials, handling and climate issues.
The Use of Antibodies and Fluorescence Microscopy
for the Identification of Proteins in Artists' Materials
Identifying the materials used in the production of historical decorative arts is important not only for understanding their construction but for determining the methods most suitable for their restoration. Because many of the compounds used in decorative art production were proteins derived from biological sources, antibody-based immunological approaches offer a possible route for identifying these materials.
To determine the viability of this method, we prepared a sample board of gesso, paint and metal flake layers with a thin (5µm) egg albumin layer in its center. This board was aged for two months at 50º C under high humidity conditions. We then performed two different assays aimed at detecting the albumin in samples of the size typically used for cross section microscopy. In the first assay, sample board of approximately 1 mm2 was dissolved in buffer and then incubated with an albumin-specific primary antibody for 1 hour at 37º C. Subsequently, the albumin-bound primary antibody was labeled with a secondary antibody conjugated to the enzyme alkaline phosphatase for 1 hour at 37º C. This immunologically-bound product was then subjected to an enzymatic assay to detect alkaline phosphatase activity, a reaction in which the amount of activity, assessed by spectrophotometer, directly correlates with the amount of albumin in the sample. Enzymatic activity was detected in all samples containing albumin, but was absent in all samples lacking albumin and in all samples in which either the primary or secondary antibody was omitted from the assay.
While this enzymatic approach permits detection of very small quantities of antibody-labeled protein, one drawback is that it disrupts the integrity of the sample. To overcome this limitation, we designed assays in which samples which had been embedded and prepared for cross section microscopy were incubated with primary anti-albumin antibody from 5 to 60 minutes, at 37º C, and then subsequently immunolabeled using a secondary antibody conjugated to various fluorophores for 5 to 60 minutes, at 37º C. The antibody-labeled samples were then imaged using reflective ultraviolet microscopy. As expected, fluorescent labeling was evident in the layer containing albumin, but was absent in all other layers and in samples in which either the primary or secondary antibody was omitted from the assay.
We are presently determining the applicability and limitations of such immunologically based approaches. Conceptually, these approaches offer the advantages of high resolution, high specificity, and substantial flexibility. Commercially available species-specific antibodies exist for many proteins known to be used in decorative art production (e.g., bovine collagen, rabbit collagen, fish collagen); commercially unavailable antibodies for any protein can be generated for moderate cost. The same sample can theoretically be probed multiple times, and with multiple antibody combinations. Limitations are likely to include protein stability in the sample over time, and the possible disruption of water-based compounds in samples during assay.
This paper presents the conservation of a mid-nineteenth century Concord Coach belonging to the Gene Autry Western Heritage Museum located in Los Angeles, California.
Years of heavy commercial use, abandonment, and haphazard restoration, prior to it becoming part of the Autry collection, transformed the once highly decorated and finely upholstered vehicle into the "hulk" that affectionately came to be known as "Old Smokey."
Multiple applications of varnish, atop years of accumulated dirt and grime, had completely obscured the original painted decoration and gilding as well as most of the visible evidence needed to determine the degree of preservation or degradation of those earlier surfaces. Initial investigation, using cross sectional paint analysis and preliminary cleaning tests, revealed a deeply cupped and cracked paint layer that could be easily damaged and abraded as those disfiguring varnish and grime layers were reduced.
In addition, the conservation of the remaining sections of the original leather upholstery is reviewed, as well as the development of a functional, “tackless” upholstery system that was required to reinstall the conserved and replicated leather components needed to complete the vehicle’s interior.
Between the shoreline of the Prince William Sound and the Wrangles mountains rising in quick elevation, stands the Valdez Museum. Within, one can find installed a locally cherished large artifact, the 45-foot front and back bar of the historic Pinzon Bar from Valdez, Alaska. The in situ conservation work continued while the museum doors remained closed to visitation. The conservation treatment intent was to stabilize as much historic material as possible and return its appearance as it was prior the 1963 earthquake. Yet, to treat the bar for a museum setting, a cleaner look precipitated from our efforts. By replacing lost elements, stabilizing structural insecurities, and reforming the historic coating; the bar now exhibits "continuity, dignity, and permanence"
With more than a million and a half historic objects, located at over three hundred sites scattered across the country, NPS museum collections are truly extensive and diverse. They are housed and displayed in virtually every ecosystem and climatic zone in the land.
How the collections are displayed is equally diverse. They are exhibited in traditional museum settings like that at Ellis Island, furnished historic structures such as the Vanderbilt Mansion, and work environments as far removed as Edison's laboratory complex and the Kennecott Copper Mine in Alaska's interior. Collection storage conditions range from state of the art, climate controlled facilities to stalls in maintenance yards adjacent to the park backhoe, and everything in between.
As wooden artifact conservators we are all familiar with a good many of the artifacts found in these collections, such as furniture and objects associated with giants in American history: things like Abraham Lincoln’s shaving mirror and Teddy Roosevelt's big stick. But the Park Service also has numerous wooden artifacts in its collections that most of us don’t deal with on a regular basis. They are typically utilitarian, large and found outdoors. They are not necessarily pretty and don't fit neatly into exhibit cases, storage areas or established conservation categories. It is unfortunate that these objects have not received the attention they deserve from the preservation community, for they are often most in need of conservation treatment.
These objects can be difficult to deal with both from a practical and a philosophical perspective. As conservators we like to think that our treatments will provide a long term or even permanent state of preservation. With wooden objects housed outdoors the reality is that treatment will need to be repeated on a regular basis to ensure even short term preservation. Since wooden artifacts cannot remain outdoors indefinitely without suffering significant deterioration we are faced with the question of when to suggest placement in protective storage or display. Does it make more sense to attempt to preserve an artifact in its cultural context for the short term or remove it so as to preserve it for the long haul?
In this presentation I will touch on the nature of the problems that typically affect these artifacts and how the most significant problems tend to vary from region to region. The general approach we in the Park Service have taken in preserving these objects and some of the specific treatments that have been used in the past will also be discussed.
I will also put out a plea for help We need the input of conservators from a variety of disciplines and the support of the science community to come up with techniques and materials that will preserve these objects in their cultural context for as long as possible. We also need to refine our approach to their preservation and think about ways to preserve the cultural information they possess when the objects themselves can no longer be preserved.
New research in the archives of Federal Boston reveals that technological innovations in woodworking machinery and methods were much earlier than we have imagined. Evidence is now clear for steam powered sawmills, early table saws, small up and down veneer mills, tenoning machines, and water driven power planers. All of these first appeared in the period 1790-1810 according or newspaper advertisements, court and tax records, and patent applications.
The paper will review a sampling of these findings, and a few pieces of furniture which appear to show marks of these early machines. The evidence will suggest we need to be extremely cautious when assigning dates to furniture with such marks. And care is also advised when deciding whether a particular furniture element is original or replaced.
Decorative Arts conservators occasionally encounter rare survivals of objects in near-original condition with good provenances. These finds are important not only for the artistic and historical information they convey, but also because they become known entities to which other objects are compared. Together with four side chairs, each with winter and summer slip seats, and two pier tables, this neo-classical Grecian-style couch with an eastern-shore Maryland early nineteenth century provenance is one such example. A close examination of the couch reveals a well-preserved original Rosewood faux-grained and gilt surface, original casters, all of its under-upholstery, a bolster, and a good portion of its original show cover and tape trim. In the course of the treatment and the additional study that followed, other elements of the couch clearly exemplify an emerging pattern of economic and technological practices of the nineteenth century.
Tortoiseshell plates, or scutes, primarily from greenback and hawksbill sea turtles have been used for centuries as both applied decorative veneers and in-the-round artist's materials. However in recent years this material has been lost from the craftsman's palette due to it being declared contraband via CITES and other public policy directives. Uses for tortoiseshell and its imitators include wide ranging artistic expressions, such as fashion accessories, jewelry, veneer on the surface of furniture and decorative wooden objects, and countless disparate objects d'art.
Attempts to replicate genuine 2-6mm thick tortoiseshell plates far predate CITES, and have had a mixed history of success. Bovine horn pastiches can be very effective substitutes, but are difficult and time consuming to make. A variety of natural resins and synthetic plastics have been employed also for these purposes, and even become valued art forms in their own right, but the plastic faux shell was generally not satisfactory for many traditional craft techniques and other applications normally employing the genuine article.
While the aesthetic character of some faux tortoiseshell was excellent, the physical properties were often too dissimilar from the genuine article to be used in the same traditional craft manner. For example, some formulations of the synthetic polymer matrix contained ingredients that compromised many traditional gluing and finishing practices and applications, boullework marquetry being among the most notable. Finally, the synthetic polymers are relatively unstable over time, certainly in comparison to the centuries that the genuine material has been used.
These and other related topics will be included as the presentation provides a chronicle of the technology and conservation treatment of a small English boulle-work box of tortoiseshell and brass. Consolidation of the lifting veneers, straightening of the bent and damaged brass-work, and replication of original engraving are presented. In addition, the topic of creating faux tortoiseshell for the specific repair/replacement will be covered in detail.
The author will conclude with a hands-on demonstration of the manufacture of the patent-pending "tordonshell" imitation tortoiseshell, which can be used for both fabricating new artwork and restoring old. Tordonshell is a cross-linked protein polymeric laminar material whose physical properties and appearance can be explicitly controlled by the fabricator by the components and processes chosen during the fabrication, resulting in materials sympathetic to almost any specific restoration project. Used properly, the process and materials can yield a material to closely imitate the pattern, color, rheology, and workability of genuine tortoiseshell.