Use of the Volatile Binder Menthyl Lactate to Temporarily Consolidate and Transport the Earthquake-Damaged Wooden Crucifix of Santa Maria Argentea in Norcia

This contribution illustrates the research focused on the process of securing and the transportation prior to the conservation treatment of a wooden Crucifix—severely damaged in 2016 during the earthquake of Central Italy—through the application of menthyl lactate. The preparatory and paint layers of the polychrome sculpture are extremely fragile due to decohesion issues and the presence of unstable cleavages and losses linked to severe thermo-hygrometric variations. Many scientific and application tests were carried out in the laboratory and then, later, on a fragment of the Crucifix in order to identify the volatile binder best-suited to this case study: menthyl lactate was selected among six binders as the most appropriate compound due to its effective consolidation, lower sublimation rate, negligible residue, and non-hazardousness. Lastly, a very specific transportation system was designed and realised to move the work, without further loss and damage, from the storage building where it was kept in Spoleto to the conservation department of the Opificio delle Pietre Dure in Florence. The volatile binder will continue to be locally applied to allow the mechanical cleaning, in order to remove the thick deposits of debris without damaging the colour. The conservation treatment will be carried out in the future, in parallel with further scientific tests.