I can mix all this powder into that little bit of water to make a casting slip. How?

This is 8.4L of water (in the bottom of that pail) and a 20kg bag of Polar Ice porcelain casting clay. Amazingly, it is possible to get all that powder into that little bit of water and still have a very fluid slurry for casting. The volume will increase to only 2/3 of this 5-gallon pail. How is this possible? That water has 100 grams of Darvan 7 deflocculant in it, it causes the clay particles to repel each other such that I can make a liquid with only a little more water than is in a throwing clay! All it takes is a few minutes under a good power propeller mixer.

Related Pictures

This is how much casting slip 10,000 grams of powder makes

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There are 8.8 liters of slip in this 2 imperial gallon bucket. The cone 10 stoneware slurry was propeller mixed in a larger bucket. First I stirred about 3/4 of the projected 44g of Darvan into 4000g of water. Then I dumped in 10,000g of the powder (shaken in a plastic bag) and let it sit to slake as much as possible. Then I used a high-energy propeller mixer, and to finish, trickling in extra Darvan until the rheology was right. The slip itself thus weighs 14 kg (31 lb) and has a specific gravity of ~1.75. It has sat overnight and formed a film on the top, but has not settled (indicating that it likely is not over deflocculated). The casting process enables even a hobbyist to make his own custom recipes and tune them over time. Would you like to develop a recipe? An account at Insight-live.com is the first step, that’s where you’ll keep all the development notes, pictures and data.

Videos

Links

Glossary

Deflocculation
Deflocculation is the magic behind the ceramic casting process, it enables slurries having impossibly low water contents and ware having amazingly low drying shrinkage

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