Abstract: A platinum welded structures are provided with a first oxide dispersion strengthened platinum or platinum alloy portion and a second oxide dispersion strengthened platinum or platinum alloy portion welded to the first platinum or platinum alloy portion. The second portion is welded to the first portion with a weld joint including a platinum or platinum alloy weld bead. The weld bead further includes at least one member selected from the group consisting of Zr, ZrO2 and rhodium at a level greater than the first and second portions. A method of making a platinum welded structure is also provided.

Abstract: Apparatus and methods for making glass are provided. The apparatus comprise a first glass melt station and a standpipe. The standpipe includes a first end portion in fluid communication with the first glass melt station. The standpipe further includes a gravity trap that is configured to inhibit formed impurities from traveling from at least a portion of the standpipe through the first end portion of the standpipe. The methods comprise the steps of providing the first glass melt station with glass melt, sensing a condition of a quantity of glass melt within the standpipe, and inhibiting formed impurities from traveling from at least a portion of the standpipe through the first end portion of the standpipe.

Abstract: The present invention is directed toward a method of reducing contamination of a glass melt by volatilized precious metal oxides that may condense on the stirrer shaft of a stirring vessel and fall back into the glass melt, by heating the shaft. In one embodiment, the stirrer shaft includes an interior cavity and a heating element disposed within the cavity. The heating element heats the shaft to a temperature sufficient to prevent volatilized materials from condensing on the surfaces of the shaft.

Abstract: A method of reducing metal loss from the refractory metal of a stirring apparatus for stirring molten glass, and the apparatus therefore are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. The apparatus may have surfaces adapted to reduce a flow of molten glass over the surface, thereby forming a layer of stagnant, or quasi-stagnant glass on the surface of the stirrer. Adaptations may include grooves in a surface of the stirrer impeller blades, or holes through the stirrer impeller blades.