Well the title says it all. We are planning on mixing all of our own clay, but last year just got a little too crazy and we didn't have time to mix enough clay up to last us over the winter. We fired our little test kiln last week. Quite a few of the pots had large bloats on them, between an inch and two inches in diameter. Here is a picture of a pot we broke, kind of a cut away view of one of the bloats:
Here is a piece from one of the bloated pots:
I'm guessing our clay supplier is have pieces of metal (iron) falling off of his clay mixing equipment into the clay body. Does anybody else out there have any experience with this, or any advice? We do fire the little gas test kiln pretty quickly. We are hoping in the extended firing of the wood kiln we can fire slow enough and keep it in oxidation long enough that the bloating will not be a problem. Still a little worrisome though as all the pots that we have made so far are made with this clay body. As soon as the weather warms up a little more we will be getting back to mixing our own clay!