Waiting for an update on the conservation and restoration of our Horten H IX V3 “Bat-wing Ship?” Here’s the latest! Our conservation staff, in collaboration with curator Russ Lee, is working with the Smithsonian’s Museum Conservation Institute (MCI) to figure out the materials and technologies used to craft the Horten H IX V3. For example, the transparent canopy was analyzed with a portable Raman spectrometer and determined to be a polymethyl methacrylate (PMMA) plastic. PMMA was developed by Rohm and Haas in the mid-1930s in Germany and the United States, and the material is reputed to have been incorporated quickly into aircraft canopies, gun turrets, and transparent noses. It is lightweight, impact resistant, relatively easy to form, and transmits light even better than glass. In this instance, identifying the canopy as PMMA confirms what we already expected from our research of trade literature from that period. It also shows how studying our collection, visually and with analytical tools like MCIs Raman spectrometer, provides direct physical evidence of an aircraft’s manufacture, which enriches our understanding of the history of early plastics in aviation.
Raman spectroscopy identifies materials by shining a laser beam at a surface and measuring the energy distribution of inelastically scattered light. It is potentially non-destructive and does not require removing a sample from the aircraft. MCIs spectrometer weighs only 6 lbs. and fits in a convenient “carry on” sized suitcase for trips out to the Udvar-Hazy Center and other Smithsonian museums.
Lauren Horelick is a objects conservator in the Collections Department of the National Air and Space Museum.