An electrolytic stabilization treatment was conducted on a BMW 801D-2 radial aero engine, which had been rescued from the Loire River near Orleans, France in 1990, after having been submerged for some 45 years. Conducted at the laboratories of Groupe Valectra Electricite de France, St. Denis, France between May and June 1992, this project follows another successful treatment conducted on a similar engine at the Conservation Laboratories of the Australian War Memorial the previous year. The process involves the removal of superficial concretions and the extraction of chloride species from within the corroded metal using an electrolytic process designed so that large objects of technology may be treated as a whole. These items may be termed composite objects, consisting mainly of aluminium alloys, iron alloys and organic material. -- CAL