In other exciting news, I found a recipe for a cone 6 casting slip. And so far, so good. I'm going to have to experiment with glazes soon, but I did an absorption test and it weighed 200 grams before and after a night of soaking in water. That means the clay is vitreous, which in the world of all things functional, is a very good thing.
Another test I did was a stress (thermal shock) test. I took the finished piece from extreme temperatures in a short amount of time. First from boiling water in the microwave to freezing in my fridge. This also was a success!
I ordered some cone 6 glazes a few weeks ago, but my supplier experienced a fire. I put another order in today, and hopefully it will make it here before too much of my vacation is over. Now all I have to do is figure out how I'm going to get some glaze tests done, considering I have no slip cast work bisqued. :/