Journal of the American Ceramic Society

doi: 10.1111/j.1151-2916.1933.tb17000.xpmid: N/A

Lovejoy, Ellis

doi: 10.1111/j.1151-2916.1933.tb17001.xpmid: N/A

ABSTRACT Stiff‐mud test bars were dried from one surface, and the rate of water loss was determined by frequent weighings. The plotted curves indicate an end point in the water movement with a loss of around 60% of the total water. This loss was checked by soluble salts in the clay and alkalinity tests at intervals.

Sosman, R. B.; Warren, B. E.

doi: 10.1111/j.1151-2916.1933.tb17002.xpmid: N/A

Taylor, W. H.

doi: 10.1111/j.1151-2916.1933.tb17003.xpmid: N/A

Nahmias, M. E

doi: 10.1111/j.1151-2916.1933.tb17004.xpmid: N/A

doi: 10.1111/j.1151-2916.1933.tb17005.xpmid: N/A

Norton, F. H.

doi: 10.1111/j.1151-2916.1933.tb17006.xpmid: N/A

Dalton, R. H.

doi: 10.1111/j.1151-2916.1933.tb17007.xpmid: N/A

ABSTRACT An apparatus is described for extracting the gas from glass at glass‐furnace temperature and determining its composition. Results are given for glasses of various compositions and various melting histories. All ordinary glasses were found to contain appreciable quantities of dissolved (or chemically combined) gas, the amount varying from a few hundredths to a few tenths per cent. Water is frequently the most abundant gas, the content being highest in borosilicate glasses. Carbon dioxide is also usually present, the amount depending on the basicity of the glass. Nitrogen, carbon monoxide, and hydrogen were never found present in appreciable quantities. All oxidized glasses contain some oxygen. Glasses containing arsenic give off a comparatively large volume of oxygen. The effect of this oxygen on fining is discussed. It has been found that remelting a glas has little effect on the gas content. The gas content is greatly influenced by the size of the melt, being the lowest in small experimental melts.

Ebright, H. E.; Hansen, J. E.

doi: 10.1111/j.1151-2916.1933.tb17008.xpmid: N/A

ABSTRACT It has been demonstrated that the small bare spots evident in the first coat of acid‐resisting enamel applied directly upon the ground coat are not necessarily the result of a process fishscaling in the ground coat during the firing operation, but are more often the result of reboiling of the ground‐coat enamel and lack of film strength in the yet unfused layer of acid‐resisting enamel. Reboiling, or other mechanical movements of the ground coat, may promote defects in acid‐resisting enamels which would not be visible in those of the nonacid‐resisting type, particularly when these enamels are applied directly upon the ground coat. The electrolytes used with acid‐resisting enamels are directly connected with the popping condition noted. A choice of the proper kinds and amounts of electrolytes for “setting‐up” the enamel can, in some cases, eliminate or minimize this trouble. The use of a nonacid‐resisting enamel, properly set up as an intermediate layer between the ground coat and the finish coat of acid‐resisting enamel, will also prevent troubles of this kind. The tendency for this peculiar defect to occur depends also upon the type of enameling base metal used and its tendency to reboil.

Baker, Ralph W.; Joublanc, J. C.

doi: 10.1111/j.1151-2916.1933.tb17009.xpmid: N/A

ABSTRACT Since all ferrous materials contain within their structure a varied assortment and quantity of gases, a discussion is presented of the effect of such factors as time, temperature, atmosphere, and deliberate methods used in the manufacture of enameling iron. A study of the important gaseous impurities in ferrous materials is given. Melting investigations were made to deterrninc at high temperatures the absorptive capacity of specially prepared irons for air, nitrogen, hydrogen, and carbon monoxide, and the influence of carbon, manganese, silicon, and aluminum on the absorptive and retentive capacities. Manganese in increasing amounts increased the absorption of all gases. A critical percentage content of 0.25% of manganese was found to exist, at which maximum absorption of nitrogen occurred; below and above this percentage content the absorption of nitrogen decreased. Many grades of enameling iron were subjected to a similar investigation. Certain irregularities of various analyses of commercial irons were noted in that there were irregularities of absorption and retention of gases in a range of temperature which included the temperature at which porcelain enamels were fired. The enameling iron of low carbon and low manganese content, containing only the permissibly low phosphorus, sulfur, silicon, and alloying elements, should insure dependable performance during enameling operations.