Step 6: Casting Your Foot: Casting
You will need about 5 cups of your casting material for an average male shoe size (estimate). I am going to use Permastone, which is inexpensive and more durable than plaster. If you find yourself short of material, you can add filler in the form of napkins (as with the alginate mold) or powders like sawdust.
Mix your material according to its instructions and pour it into your alginate mold. Put your bowl and mixer in the sink under running water while you work to minimize the risk of damage to your tools.
1) Tilt your box back and forth to make sure you get it into the toes and crevices.
2) Tap the sides of the box hard, shake it against the ground, and continue tilting it until to force air bubbles to the surface. This is satisfying.
Remember though, we're doing this cheap and easy, so your mold probably won't be perfect and that's OK.
Let your cast sit until you're sure it's dry.
Note: I am using PermaStone, which is pretty cheap ($6 a box), but you can substitute another material such as rubber if you have the means. I do not recommend plaster, as it takes forever to dry and it is fragile.