Case Studies in Sustainable Collection Care Session, Friday May 30th, 2:50pm
Securing The Future of Collections in Zimbabwe’s National Museums through Preventive Conservation: The Case of Zimbabwe Military Museum
Presenter: Davison Chiwara, assistant lecturer Midlands State University, Archaeology, Cultural Heritage and Museum Studies Department at in Gweru, Zimbabwe
This presentation reported on the analysis of collections care and sustainability at the Zimbabwe Military Museum, and presented recommendations to improve policies and practices. Mr. Chiwara’s presentation provided an important example of profound challenges to cultural heritage preservation faced by museums with restricted financial and organizational resources.
The Zimbabwe Military Museum was founded in 1974, at the end of the civil war in then Rhodesia, and five years prior to the official recognition of the nation of Zimbabwe in southern Africa. The museum is located in Gweru, Zimbabwe approximately 165 miles / 265 km southwest of the capital, Harare.
The analysis of storage conditions, environmental controls, and maintenance practices were evaluated using a survey document, interviews, and first hand observation. Mr. Chiwara’s investigation identified poor storage conditions and the lack of functional policies or guidelines for collections care. The museum has no purpose-built storage structures, and the existing artifact storage areas lack humidity, temperature, UV light or pest controls. Examples were presented of an accessioned structure that is currently being used for artifact storage, mold forming on artifacts, water damage, direct sunlight on artifacts, and inadequate housing for archaeological collections.
The museum does not have a collections management policy. A “draft paper” defining a collections policy has been drafted but not accepted by the governing organizing: National Museums and Monuments of Zimbabwe, creating a situation in which the Military Museum does not have a functioning policy nor is it empowered to create its own.
In conclusion Mr. Chiwara stated that preventative conservation is required to preserve the collection, and posited that preventative conservation must include reducing both short and long-term costs. He argued that investment in collections care now is crucial to achieving both of these goals and he recommended establishing standards for collections care and guidelines for implementing preventative conservation practices.
Author: CaseyMallinckrodt
AIC’s 40th Annual Meeting, Joint Sessions: Objects + Reseach and Technical Studies, May 9, Some Unusual, Hidden, Surprising or Forgotten Sources of (Possible) Sulfur Contamination in Museums and Historic Buildings
Presenter: Paul Benson
Sulfur is well known as an agent of deterioration associated with atmospheric pollution, but sulfur was, and still is, intentionally introduced into buildings as part of the construction process, and is a part of some objects in museum collections. This presentation by Paul Benson was tremendously informative about how sulfur may be hiding in plain sight and damaging collections. The talk provided examples of the use of sulfur past and present, and provided an example of effective control of sulfur used in the construction of an exhibition space.
Molten sulfur is an excellent electrical insulator. It has very good adhesive, handling, and casting properties that make it a good fill material. It goes through a flexible stage when cooling and it expands slightly (3%) on setting. In the US plaster ceilings were repaired with molten sulfur until the 1920s and buildings built before 1940 may have sulfur behind the surface of the walls as an insulator or fill material. Conservators carrying out CAP surveys should be mindful of these possibilities.
There are unsuspected modern uses of sulfur as well. Used as an inexpensive filler in Chinese-manufactured dry wall imported to the US between 2001 and 2009, it caused extensive damage and reconstruction. Sulfur with additives is used instead of Portland cement in Canada because it has considerable shorter set time.
The Nelson-Atkins Museum discovered that the cause of severe mottling of bronze sculptures was sulfur applied behind the numerous travertine sides of display cases integrated into the structure of the walls. This situation was successful remediated by removing each piece of travertine, and applying Marvelseal® with Beva®.
Sulfur has been used as a fill material in bombs. Police forensics use sulfur to take very accurate casts of footprints in snow. These objects may be stored for long periods of time and contaminating other evidence.
Molten sulfur has been used since antiquity as an adhesive. Pliny may have described its use as an adhesive for glass (depending on the translation). Sulfur was used as an adhesive in Rome, Greece, and Byzantium. All stones in the Thetford treasure at the British Museum were set with sulfur. Sulfur was used to secure iron rods holding together elements of stone sculpture.
Sulfur can be found as an inlay material in furniture marquetry particularly in the sixty years from 1760 forward. Sulfur will take on the appearance of mother of pearl with repeated heat treatments and can be found as “pearl” inlay on guns and guitars.
Objects may be made of sulfur. “Spences Metal” is an iron-sulfur alloy used in the years around 1880. It can take a high polish and imitate a variety of metals. At the time hoped to be in inexpensive replace for bronze. “Ebonite” was made of rubber with 30-40% sulfur and was used to manufacture buttons and casters for furniture among other utilitarian objects that may be in museums of attached to objects in a collection.
Sulfur has been found in an historic clock cast around the weight to hold it in place. The “lead” of German pencils made before 1770 is a combination of graphite mixed with sulfur. Coins may have been cast in sulfur lined plaster casts. And among the seemingly innocent items that might be in a conservation lab sulfur is present in Plasticine® and pencil erasers.
This presentation provided a useful warning about possible contamination from sulfur present in unpredictable places and provided a wide range of examples to guide in hunting for an unseen source of corrosion.