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The following glazes are unsuitable for use on surfaces which may come into contact with foodstuffs or beverages: Gold Lustre, Graphite, Lime Green, Flame Orange, Signal Red and Bright Yellow. All others are non-toxic and food safe when applied in the normal manner. CADMIUM SELENIUM GLAZES The toxic glazes containing Cadmium Selenium are bright and vivid, lending themselves to decorative pottery. However to achieve these brilliant results car must be taken with their application and firing as they are more sensitive than other glazes. the following suggestions are given to assist customers to get the best results. APPLICATION 1. These glazes should only be applied to hard-fired bisqueware. 2. Glazes should be applied about the same thickness as the average coloured opaque glazes. Too thinly glazed pieces tend to show clear breaks or patches. Too thickly glazed pieces may develop an "orange peel" or rippled surface, or black spotting. 3. Make sure all pieces are thoroughly dry before setting into the kiln. 4. If too much water inadvertently has been added to the glaze, do not let the glaze settle and pour off excess as is normally done with other glazes. In such a case, add more dry glaze until the desired consistency is achieved. FIRING 1. These glazes are intolerant of steam and other kiln gases. For this reason , only dry ware (previously bisqued) should be set; do not attempt to fire greenware along with these glazes. Greenware should be fired separately to avoid other glazes "striking" them, causing loss of quality, patchiness, blackening or blistering. Electric kilns are preferred; if a gas kiln is used, the pieces must be set in saggars or the kiln must be fully muffled. 2. Do not overcrowd the kiln, or set pieces to close to elements, walls, kiln furniture, etc., or blistering or clear and/or blackish patches may result. 3. Firing temperatures vary with the time taken over approx. 700°C. For a rapid fire, say 6-7 hours to peak, the glazes will withstand 1000 -1080°C. For slower fires, the temperatures should be reduced somewhat. Excessive raid cooling (by opening the doors. etc.) is not necessary but plugs should be removed as soon as firing is completed, to ensure a naturally rapid cool. Some experimentation may be required to find the optimum procedure for the potter's own conditions.
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