Overall, I think I'm pretty happy with the way the ash glaze turned out (particularly the dark green one). One glaze turned out a dark green-to-black, and the other was an opaque gray that I'm not crazy about. In some places, for reasons I don't understand, the glaze had beautiful blue and white streaks in it. This seemed to happen more where the cups received the most fly ash from the firing.
About half of the mugs that I made from the iron-bearing clay body warped excessively or split during the firing. Some split, and then were healed again by the melting glaze. Others, not so fortunate.
I think in the future I'll be doctoring the clay body a bit with other materials to help it handle the firing better.
Here are some of the results:
