The Supervisor of the Laboratory at the Museum of History and Technology, Smithsonian Institution, describes his experiments with the restoration of modern machinery - a field in which no printed data exists. After testing the efficiency of traditional methods of removing old paint, grease and rust from iron and steel, Mr. Henson discovered that the Magnus Chemical Company caustic cleaner 61-RDX was superior to all other stripping agents. The Magnus FF 111 clear coating was the most effective method of preventing the recurrence of rust spots. References are given to other materials used in the process of restoring the parts of machinery, ranging in date from the 1870's to the present time.