Remember aaaages back, when I mentioned playing with hazardous materials but never really elaborated on it? I got to do it again. And am too sore and wired to fall asleep right now, so you finally get to hear about it.
I was reclaiming clay. When potters make things, especially on the wheel, there are lots of stray scraps of clay that get generated. Long strips that get trimmed off the bottoms of things, finished items that cracked while drying, mugs that fell off their handles when you absent-mindedly pick them up by the fragile little handle so they fall on the floor and shatter into a million jillion pieces–those sorts of things. These scraps can be collected, allowed to dry out completely, and recycled back into usable, “reclaim” clay.
Collect scraps! When they are completely, utterly bone dry, fill some buckets with water and pour the scraps in. (DO NOT STIR YOU WILL SCREW UP THE PARTICLES. Water will not be able to rehydrate the pieces of clay, especially larger ones; you will end up with a thin layer of wet clay over a piece of bone-dry clay. This is not usable.) Let the mix sit overnight. Or longer, for smellier but smoother results.
You now have buckets of slip! This is basically very watered-down clay. Pour off the watery bit on top, and pour the more solid slip into your handy dandy clay mixer. (Cement mixers work too.)
This is, by the way, is the point at which you really need to put on a smock (to minimize silica contamination of your clothes) and a respirator. Ignore the Darth Vader jokes. They are made by people who clearly know nothing of Star Wars.
Add a few pounds of powdered, dry clays (our studio’s recipe calls for mostly Kentucky ball clay and Old Mine #4, with a dash of EPK kaolin), and a couple pounds of silica and feldspar. If you want to get fancy and make coloured clay, add varying amounts of iron for browns or reds, cobalt for blue, or copper for greenish. You can also experiment with stains for other colours, but you’re getting into pretty darn expensive territory there.
Keep adding dry materials until your clay is the consistency of clay. Scrape it out of the mixer (this is the hardest, most back-abusing part), wedge it into manageable blocks, and wrap it in plastic.
Ta-da! You have clay! Go make something with it!
 Yeah, he wheezes, but his wheeze is all cool and sinister and evil and stuff. A potter in a respirator sounds more like your asthmatic little brother just after you’ve accidentally nailed him in the gut with a hard rubber ball during a game of “no contact” dodgeball.
 Sorry, Erik.