I've been putting this off for a while because I've been scared of screwing it up. Oh well, nothing ventured, something something something.
There's basically two options for lining. Buy a commercial product or make your own. The commerical products are better, more durable, and probably easier to work with. But, they tend to be expensive. I opted to make my own. I used the recipe from the Gingery book, which is basically fireclay and sand, as a starting point. I used the straight recipe for foundry 1.0 and it worked well but wasn't very durable. This time around, I added perlite and borax which I've read helps improve the finish. We'll see.
I mixed the ingredients on a plastic tarp and added just enough water to get the right consistency. Then cover it and let it sit overnight.
The shape for the bottom of the chamber is wax mold I made by melting about 5lbs of parafin into my wife's mixing bowl. Freeze it overnight and it pops right out. I screwed a handle into it to help pull it out. I did the same for the top but not as deep.
After ramming it tight and pulling out the forms, we have the completed lining ready for firing.