AIC's 52nd Annual Meeting

Conservation treatments done in museum settings often include the use of archival adhesives and high-grade solvents obtained from approved vendors. However, many of the objectsinmuseum collections have been made or previously repaired with adhesives that are not considered archival or conservation-grade, complicating the work of conservators that attempt to remove them. of special interest are thermoset and aged thermoplastic adhesives as they are virtually impossible to remove with traditionally-used solvents, together with the possibility of irreversible damage caused by their removal.

At the Yale Peabody Museum, after encountering numerous objects that had adhesives not affected by traditional solvents, we decided to search for non-traditional options. Previous work done on the removal of epoxy from a mastodon tusk using pineapple juice inspired our search for novel ways to treat objects. The long-term effects of epoxy resins have been known in conservation for decades, including persistent issues with aging properties and reversibility. Epoxies have been historically used in glass restoration but its use is not reserved only for this purpose; preparators and collectors often use it on large, heavy fossils and minerals due the adhesive’s strength in comparison to conservation-grade adhesives. The need to reverse epoxy joints that do not have a reversible adhesive barrier becomes fundamental for several object materials.

The goal of this work was to test the effectiveness of pineapple juice, as well as papaya and kiwi juices in the removal of aged adhesives, both from older objects and test samples. Older objects containing visible adhesives obtained at thrift stores were employed as test objects. Samples were obtained and analyzed using Fourier Transform Infrared Spectroscopy (FTIR) at the Institute for the Preservation of Cultural Heritage at Yale University. In addition, samples were prepared on plexiglass using adhesives known to have been used in the repair of objects, especially by the general public. These were then aged artificially. For the removal of the adhesives, all samples were treated with pineapple, papaya and kiwi juices, as well as with their corresponding enzymes (bromelain, papain, and actinidin, respectively).

Preliminary results suggest that the pineapple juice is able to soften some aged adhesives, which can then be removed mechanically. Not all objects are suitable for this kind of treatment, due to the possibility of staining, damage, and even increased risk of pest activity.

The most important goal of this study is not the identification of which adhesives these juices are able to remove or even whether the isolation of the enzymes is a better technique altogether, but to find a simple, non-hazardous method of adhesive removal in conservation. This goal becomes especially important when considering that many institutions worldwide are not able to purchase certain solvents as part of their daily practice due to cost, availability of high quality options, and even national security concerns. We hope this study is a first step in finding a good solution to a problem that is widespread in conservation.