Salty Bricks and Varnished Spouts: May 2025 Conservation Updates
With the winter semester now wrapped up, the Kelsey Museum’s conservators are enjoying a brief respite from assessing objects for class visits, but that doesn’t mean the lab is any less busy! Read about the projects that Carrie Roberts and Kathryn Peneyra—conservation fellow at the Kelsey—have undertaken over the past few weeks.
Conserving a Horse-Head Spigot
The Kelsey Museum will soon open its next Crossroads of Culture Object Spotlight, curated by members of the Kelsey graduate student community. This exhibition, exploring the interplay between humans and nature in the Middle East and North Africa, will display nearly 70 objects—all of which need to be evaluated prior to installation.
One artifact that Carrie investigated was a Roman-period spigot (KM 4975) from Fayum, Egypt. This bronze water spout is shaped like a horse head, with circular openings at both ends. In addition to its visible corrosion, the object’s condition was exacerbated by a varnish placed on it in the 1970s.
To address these issues, Carrie soaked the object in three successive baths of acetone. Between baths, she was then able to remove the powdery, pale green corrosion from the spigot’s interior surface using bamboo skewers, a scalpel, and ethanol swabs. A final acetone soak and an overnight bath in a corrosion inhibitor have ensured that the object can safely be displayed in the temporary Crossroads spotlight.


Investigating the Kelsey’s Salty Bricks
In the 1920s, Francis Kelsey purchased a collection of hundreds of stamped Roman bricks that are now part of the museum’s permanent collection. The bricks were stored in wooden cabinetry from then until the 1990s. During these 70 years of storage, organic acid vapor was slowly released by the wood the cabinets were made of, and this caused a chemical reaction with the salts already present in the bricks, resulting in efflorescence of big, fluffy salt crystals on the bricks’ surfaces. “In other words,” Kathryn described, “the bricks are salty! Very salty.”
The salt crystals present in the stamped brick collection cause some problems: when the salt crystallizes, it can damage the structure of the bricks; the crystals also conceal the bricks’ stamped surfaces, limiting their usability for research, classes, and exhibitions.
Kathryn characterized the salt thanks to the helpful conservation staff at the Detroit Institute of Arts (DIA), including Conservation Scientist Christina Bisulca. Kathryn used the DIA’s Fourier transform infrared (FTIR) spectrometer to analyze the chemical composition of the salts, allowing her to conclude that they were formed as a result of their past storage conditions.
Kathryn’s research on the bricks continues as she tests different treatment methods to remove the salt. She will ultimately write up a protocol for the Kelsey detailing how to treat the bricks going forward.


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