This journal article describes the conservation of corroded iron age antiquities. Treatment consists of a safer variation of the Hartwich method. The object is heated in a furnace and illuminating gas, consisting of reducing gases, passes over it. Metallic oxide forms carbon dioxide and water, oxide, free metal. Furnace construction is described. Gas enters the furnace and an attached trap evacuates water and tar. Furnace temperature of 600 Celsius is maintained with a current of 7.8 amperes in two windings for 60 minutes and then reduced to 7.8 amperes in one winding for two hours. During the procedure and cool off period illuminating gas passes through the furnace. After cooling iron powder is brushed from the objects with an electric motor-driven rotary brush. A thin, black surface layer of Fe3C has formed. Objects are immersed in molten wax or synthetic resin. In a few cases where objects could not be heated reduction of the iron oxide in water solution with zinc metal in sodium hydroxide as the reducing agent was the treatment. Two objects are reduced by a modification of Fink's electrolysis method. This describes three treatments of iron corrosion. -- CCI