The authentic restoration of scientific instruments is a technique, which needs comprehensive knowledge of technical methods and genuine recipes as well as craftsmanship and professional machinery. This talk presents the different degrees of restoration beginning from gentle cleaning to complete restoration including fabrication of missing parts. The various methods of machining and surface treatment of different materials, such as brass, bronze and steel are discussed. A few examples of instruments before and after restoration illustrate the result of successful work.

Olaf Medenbach is a professional mineralogist (retired) working for the Ruhr-University in Bochum/Germany. Since more than 40 years, he is collecting and restoring scientific instruments with special focus on mineralogical apparatus.