Progress on the Conservation of St. Mike

For those of you who are not familiar with Scripps’ St. Michael, he is a painted and gilded wooden sculpture. He was carved c. 145o, and was part of the façade decoration for an Italian church. Under the guidance of L.A. conservator Donna Williams, I have been conserving our 560-year-old friend for the past nine months.My work on St. Michael has mostly consisted of gilding consolidation, a process by which I flatten and adhere flaking, cracked gilding back onto the wooden base of the sculpture. The gilding on the body has been entirely consolidated, and thanks to a couple of productive weeks and the helping hands of my fellow intern Tiffany Yau, the wing gilding should be finished within the next several days!Another integral part of the conservation process is testing. Many people, when picturing an art conservator in action, see them standing before an artwork in a studio, utensil in hand, working diligently away on the piece. Most do not see a scientist sitting before computer screens in the basement of a physics building. But while the hands-on work (called “bench work” among professionals) is inarguably the main part of the conservation process, scientific testing forms the backbone of the field. It provides the conservator with important knowledge about the piece, without which sound bench work would be impossible.The testing on St. Michael has been exciting and diverse. In April, the RCWG staff, Donna, JSD Prof. Anna Wenzel, and myself took him to Pomona Valley Medical Center for a CAT scan! You will be able to read about the scan and its results in the Fall 2010 Scripps Magazine. In May, I was trained on the scanning electron microscope (SEM) at the Pomona Department of Physics. The SEM examines the topography of a sample with a high-powered electron beam. I took micrographs of fiber samples, and by comparing them to images from the MFA Boston’s Conservation & Art Material Encyclopedia Online (CAMEO), I identified two different fibers present on the piece: linen and hemp. Fifteenth-century painters commonly used these materials to prepare painted surfaces. In the case of St. Michael, the fabric was wrapped around joints and other areas. The wrapping was then covered with gesso, a primer much like plaster.I have also begun using Energy Dispersive X-Ray Spectroscopy (EDS), a technique that is used in tandem with the SEM. This allows me to detect which elements are on the surface of a paint sample. Since different elements make up different pigments, and those pigments were discovered and used at different points in history, I will hopefully be able to approximate the date of any repaints of the blue garments on St. Michael. Although I have already begun testing with EDS, there are no certain conclusions to be drawn at this time. Updates will follow soon!