• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.158-164
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• 2004

This study is to analyze the characteristics of typical Korean wood ashes from twelve trees, oak tree needles and pine bark, which are common in the area, and to suggest their applications in ash glaze making. The chemical analysis of the ashes shows that the main component of wood ash is CaO while wood bark ash consists of $SiO_2$, and leaf ash consists of CaO and $SiO_2$. The results of the study are as follows: Ashes made from the wood of Acasia, Popular and Jujube contained relatively high amounts of Fe$_2$ $O_3$ and MgO compared to other tree ashes. The ashes had yellowish green color glaze. From the result of W analysis they presented the highest chroma. Therefore these ashes are good for making transparent glaze. From the result of W analysis Grapevine, pear and oak wood ashes containing the highest amounts of Fe$_2$ $O_3$, MgO, P$_2$O$\_$5/ and MnO presented yellowish green color glaze compared to other ashes are suitable for making opaque glazes because of their showing stable and opacity phenomena. Pine tree, Platanus and Zelkova wood ashes consist of high amounts of CaO and P$_2$O$\_$5/ compared to other tree ashes. So they showed the most vivid and bluish green color glaze among 12 ashes. Therefore, they would make a good celadon glaze. Birch, oak and chestnut tree ashes have high content or MnO which affects on glaze color with small amount. These ashes presented yellowish green color not as much strong as Acacia ash, Poplar ash, Jujube tree ash. These are good for Irabo glaze.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.834-841
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• 2004

The purpose of this study is to investigate the properties of traditional Korean ash glazes by using locally available sources; 10 kinds of grain stems,2 kinds of husks (pod, chaff), and 4 kinds of vegetables (spinach, radish leaf and stem, pumpkin leaf and stem, pepper stem), and to develop their practical uses as ash glazes. The test results of these ash glazes indicate that these ashes can be classified into four categories. The first group, which includes perilla stem ash, sesame stem ash, black bean stem ash and red-bean stem ash, shows strong milky white due to relatively lower content of $SiO_2$, and relatively higher content of CaO and P$_2$O$\_$5/ content (10% higher than others), and their glazes were found to be suitable for opaque glaze as they show relatively stable bright greenish color. The second group includes pepper stem ash, spinach ash, pod ash, radish leaf and stem ash, and bean stem ash, and this group was found to contain even quantity of every component. And their glaze show somewhat greenish color because of especially high content of MgO and more than 2% of Fe$_2$ $O_3$. They were found to be suitable for basic glaze of IRABO glaze. The third group, which includes com stalk ash, white bean ash, pumpkin leaf and stem ash, has more $SiO_2$ and Al$_2$ $O_3$ than other ashes, and it also contains 3～5% of Fe$_2$ $O_3$. As a result of those components, this third group shows the greatest change of color and chroma, and was found to be suitable glazes as basic glaze of Temmoku and black glazes. The fourth group (reed ash, rice straw ash, indian millet stalk ash and chaff ash) has as much as 45～82% of $SiO_2$ and relatively lower content of Fe$_2$ $O_3$ and P$_2$ $O_3$. This group shows blue or greenish white color, and was found to be suitable as the basic glaze of white glaze.