2.11 Evaluation of Abrasive Materials for the Cleaning of Silver Objects
Los Angeles County Museum of Art
The Getty Conservation Institute
J. Paul Getty Museum
Susan Lansing Maish
Period of Activity: 6/86 to 6/88
The objective of this project was to evaluate the effects produced on sterling silver by various combinations of commonly used generic abrasives and carrier fluids during cleaning to remove silver tarnish. Evaluation factors included amount of silver removed, ease of application and removal of abrasive, and the effect of cleaning time. The abrasives were comparatively rated on a basis of a numerical figure of merit obtained from the experimental data.
Wharton, G., S. Lansing Maish, and W. S. Ginell, "A Comparative Study of Silver Cleaning Abrasives," Journal of the American Institute for Conservation, Vol. 29, 1990, pp. 13-31.
ABSTRACT-The intent of this investigation was to identify a safe, effective abrasive cleaning system for use on museum silver. This research, performed at the Getty Conservation Institute and the Los Angeles County Museum of Art (LACMA), was coordinated with the actual cleaning, polishing, and lacquering of a large silver collection at the museum. At the GCI, tarnished sterling silver samples were cleaned using thirteen abrasives and two carrier fluids. The amount of silver removed, the relative amount of tarnish remaining, and the appearance of the silver surface after cleaning were assessed. Independent bench tests were performed by the LACMA conservation staff to compare subjectively the results produced by the various abrasives, carrier fluids, and cleaning cloths. It was found that gamma alumina gamma alumina;, green chromium oxide, and precipitated calcium carbonate suspended in deionized water containing a nonionic surfactant removed tarnish successfully and caused the least amount of damage to the silver. Polishing mechanisms and factors to be considered in selection of museum silver cleaning systems are discussed.
Wharton, G., S. Lansing Maish, and W. S. Ginell, "The Physical Effects of Abrasives on Sterling Silver," American Institute for Conservation Annual Meeting, Vancouver, B.C.E., Canada, May 18-24, 1987.
ABSTRACT-The intent of this investigation was to determine the best polishing system for use on museum silver. This research, performed at the Getty Conservation Institute, was coordinated with the actual cleaning, polishing, and lacquering of a large collection of English silver at the Los Angeles County Museum of Art. Thirteen different abrasives and polishing media were chosen to polish sterling silver samples on a polishing apparatus designed to polish in a reproducible manner. After artificially sulfiding and polishing the samples, the amount of surface material lost was measured. The samples were also characterized through visual and scanning electron microscopy. At the Museum, bench tests were performed by the conservation staff to compare the results produced by various abrasive/polishing media combinations.
Wharton, G., S. Lansing Maish, and W. S. Ginell, "Silver Polish Project Technical Report," Final Report to the (Conservation at the Getty) Institute, February 1988.
ABSTRACT-See previous two abstracts.