I first came up with the idea to create my own clay cave systems when I was surfing cichlid sites and noticed that many people were using Texas Holey Rock or Honeycomb limestone for aquascaping their cichlid aquariums. It is quite difficult to get or very expensive to purchase this when living in Canada as Ebay and other such sites rarely ship here. So I decided to make my own!
First you must wedge the clay to get the air pockets out. Wedging is an artistic term for lifting up the clay then throwing it back onto the surface you are using. A table or counter will do. Don’t throw it too hard as it may stick and be difficult to lift off again. It is important to wedge for about 10 minutes to ensure no air bubbles remain. The bubbles will expand in the kiln and cause your creation to explode.
Secondly start to design, create and have fun making caves, crevices and other fractures to create the desired look. If you do not finish on your first day for example, cover the clay with plastic wrap so it does not dry out. If it dries you will not be able to continue molding the clay.
Third you must allow the clay to dry to a "leather hard" state which means it is almost rock hard but you can still etch markings or designs upon it.
Finally you are ready to fire your creation in the kiln. You will have to call around to find a place that fires homemade products. I did not have to do this as I completed them in my art class at school and had a kiln readily available. I am therefore not sure as to exact places that do this. I am sure however that art stores could recommend local kilns.
Good Luck! □