Sahara Vases

George Debikey, Ceramic Engineer, Ceramic Artist and former Director of Technical Servies at AMACO for 33 years explains AMACO®’s Sahara Glaze Series:

The Sahara High Fire Glaze Series is a combination of different types of glazes producing a variety of surface effects. In this series you will find glazes that are so completely different that they seem to be from different glaze series. The variations between them range from gloss transparent glaze—that work great on textured porcelain and when fired show beautiful light to dark shadings of the glaze color as the glaze flows into the crevices—to glazes that are completely matt and opaque, which do not flow at all during firing and result in a solid surface. There are also those glazes that are textured and that produce a beautiful slight flow during firing giving the glaze wonderful depth of surface reminiscent of cone 10/11 (2381ºF, 1305ºC/2399ºF, 1315ºC) reduction glazes.

The Sahara HF glazes are made to fire to cone 5/6 (2205 ºF, 1207ºC/2269ºF, 1243ºC) in oxidation (in an electric kiln). However, with the exception of HF-26(Turquoise), they can also be fired in a reduction atmosphere resulting in different and beautiful surface effects.

Even though the application of these glazes can be done over bone dry greenware for single firing, it is easier to apply them over low fired bisque, in order to avoid the risk of collapsing the greenware piece due to excess water absorbed when glazing.

Glazes in liquid form are ready to use while dry powdered glazes are mixed with water to the consistency of light cream. The Sahara glazes can be applied by brushing, dipping or pouring. The Sahara glazes can be applied next to each other with a slight overlap in order to let them flow slightly into each other. Layering two or more Sahara glazes on top of each other can create infinite effects depending on the different glazes you are using. The Sahara HF glazes are numerous: you can increase their number many times and their surface effects by overlapping them. Always test fire any combination that you are using before applying it on a good piece.

The Sahara HF glazes are excellent for use on dinnerware and utilitarian ware. Use over any of the AMACO cone 5/6 (2205ºF, 1207ºC/2269ºF, 1243ºC) clay bodies whether porcelain or stoneware or any other manufacturer’s cone 5/6 (2205ºF, 1207ºC/2269ºF, 1243ºC) bodies. At these temperatures the bodies are dense and strong and can withstand utilitarian use. These glazes are also lead-free and made to produce a strong durable glass surface—perfect for dinnerware.

Attention should be given to HF-26 (Turquoise) and HF-32 (Textured Tan). These glazes should be applied thicker than usual. Since everyone’s glaze application is different, it is recommended that you test fire every glaze before using it on a final piece. Also, HF-36 (Textured Amber Brown) needs to be fired to cone 4 (2161ºF, 1183ºC) in order to obtain texture.

HF-9 Zinc Free Clear glaze was developed to especially take care of underglaze decorations. A Zinc free clear glaze is very important for underglaze decorations because the presence of Zinc in a clear glaze may change the appearance of certain colors, such as green, black, gray etc. With HF-9 Zinc Free Clear colors will be authentic. Check the Underglaze firing chart for color difference at cone 5/6 (2205ºF, 1207ºC/2269ºF, 1243ºC). Its firing range is from cone 4 (2161ºF, 1183ºC) to cone 6 (2269ºF, 1243ºC).

Sahara Vase made by Ceramic Artist, Judy Jensen.
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