Abstract: The invention relates to a method of piece by piece metal coating of thermally sensitive objects, for example optical discs. The objects are coated by being located particularly close to an evaporation source for evaporated metal. The evaporation source constitutes a melt enclosed in a crucible which is heated by inductive means. The distance between the object and the melt is kept to a few centimeters and the exposure time is kept to a few seconds in order to coat the objects without causing damage. The method includes the steps of providing an evaporation chamber containing an evaporation source of metal, reducing the pressure in the evaporation chamber, and placing the object in the evaporation chamber so that a surface of the object is opposed to a surface of the source of metal and is separated from the surface of the source of metal by a distance which is the same as or less than a dimension of the surface of the object to be coated.

Abstract: A crucible particularly intended for use when vaporizing aluminum and comprised of an ultralow cement compound. Subsequent to moulding and drying the crucible, the crucible is baked at a high temperature, which corresponds to the temperature of the crucible when used in a vaporizing process, 1,200.degree. C. for instance. The crucible comprises an outer wall and a bottom in which upstanding projections or corrugations are provided. These upstanding projections or corrugations fulfill the function of enabling gas enclosures generated when mixing the cement compound to rise up and collect in the corrugation peaks without impairing the homogeneity of the material in the actual crucible bottom.