Extra mixed alginate or plaster is not really usable so be careful to mix as close to the exact amount as you can. Cleanup is pretty simple if you ma...
Step 10: Demold
Now, you wait. The plaster should cure in thirty minutes or so, depending on how thin you mixed it. It will heat up noticably while curing. There is actually a chemical reaction going on that solidifies it, it's not just drying out. Once you can see it's no longer liquid, touch the back periodically to feel the temperature. When it's gotten warm and then cooled down to room temperature again, it's safe to take it out of the mold.
Bio:I'm a founding member of Noisebridge (https://noisebridge.net), a hackerspace in San Francisco, and Ace Monster Toys (http://acemonstertoys.org/), in Oakland. If you're in the area, stop by and say h...read more »