The structural block made from friable sandstone of the present invention includes a friable sandstone block quarried from a friable sandstone deposit in which the friable sandstone has an inherent structure providing strength, and cement disposed within the inherent structure to lock the inherent structure in place. In another embodiment, a confining jacket can be disposed about a friable sandstone block to lock the inherent structure in place. If desired, the cement or confining jacket can include a coloring agent such as a dye or pigment for aesthetic effect. The method for making structural block from friable sandstone of the present invention comprises determining whether the friable sandstone is quarriable, treating the friable sandstone in place if the friable sandstone is not quarriable, quarrying the friable sandstone into friable sandstone blocks, and finishing the friable sandstone blocks into structural blocks.

The present invention relates to ceramic foam filters having a gasket material chemically and mechanically bonded thereto. The filters have particular utility in the filtration of molten metal, especially aluminum. The filters are formed by immersing the porous filter body, preferably in a fired condition, in a gasketing medium consisting of a concentration of ceramic fibers, one or more binders, and the balance a vehicle such as water and applying a vacuum through the porous filter to draw the gasketing medium into contact with the portions of the filter body to be gasketed.

The moisture or water vapor barrier protection of a composite pressure vessel suitable for use as a composite cased solid propellant rocket motor is improved by immersing the pressure vessel, during pressure testing thereof, in a curable liquid polymer solution, optionally containing electrically conductive material such as metallic flakes or powder, so that the solution may flow into open voids, cracks or fractures in the pressure vessel and subsequently curing the curable liquid polymer in said voids, cracks or fractures.

The invention relates to a method for rapidly setting or stiffening a soft, freshly formed body such as fragile and complex thin-walled cellular substrate to prevent damage and distortions and to preserve the integrity of the substrate during the pre-firing stages of the manufacturing process. A method is disclosed for rapidly setting such objects by impregnating the object with a rapid-setting compound for a time and at a temperature sufficient to irreversibly stiffen the object, and thereafter removing any excess compound from the object. Useful rapid-setting compounds having a high affinity for water, and having appropriate molecular blocking configuration are disclosed.

This invention relates to a process for coating a substratum sheet material, such as woven fabrics, by first removing from the substratum material any moisture that does normally exist therein, and then coating the substratum material with a coating composition with no moisture, air or other impurities being trapped between the substratum and the coating. Novel products produced by this process comprise new compositions of sheet materials having improved weathering characteristics including stability against ultraviolet degradation for improved service in highly transparent or translucent coverings for roofs and solar devices.