This is a guide on how to mix, specifically a clay body I like called Glacier White which is sold by Laguna. Which you can then use to cast objects from a mold into ceramics. The whole process is called slip casting.
Done at TechShop Chandler
Step 1: Supplies
You can buy pre mixed slip at ceramics stores, however it is much cheaper and you have much more control if you mix your own.
The powder I ordered is called Glacier White, it is a porcelain that dries completely white and a little transparent. And I like how elegant it looks.
The recipe I use is passed on from an old professor
1 kg of dry clay powder
14. oz of hot water
6 grams of Darvan 7
.625 grams of soda ash
.325 grams of barium carb
a 5 gallon bucket will hold about 10 kgs of dry powder (so 10x this recipe)
First put your water in the bucket, then mix your Darvan, soda ash, and barium carbonate in your bucket. The last 3 are your defloculant if you put too much of it in it WILL ruin the entire batch. You can buy all of that at a ceramic supply store. Measure everything on a gram scale.
After that is all mixed in your bucket add your clay powder .5 kg at a time use a paint mixer attachment on a drill. I bought one at home depot for 5 bucks. Keep it under the surface of the water so you do not add air bubbles into the mixture. Once all of the clay is added keep mixing for another 10 minutes.
Step 2: Testing Your Mixture
After it's all mixed it should be about the consistency of thick cream. If you drunk your hand in it, it should run off and web between your fingers. If it feels too thick add more water NOT defloculant. If it feels too thin add a little clay powder, or wait for some of the water evaporate.
Once you're all done you can make a mold and test it out. I made a cup mold from a 3-D printed object.
This recipe is only good for Laguna Glacier White, it could work with other casting bodies but I have not tried. It's worth doing your own research with what kind of color you are looking for and what you are trying to make.
This particular body is made for casting thin porcelain small objects. It does not handle large objects too well and collapses but it looks really cool.