You will need:
- blue dish-soap (any brand seems to work)
- silicone caulking (do not buy quick set silicone, you need 100% silicone)
- caulking gun
- something you want to make a mold of.
- masking tape - to patch holes in your positive, if necessary.
Step 1: Make your catalyzing solution.
This is by no means an exact science, I use blue dish soap because it allows me to see how much I have added to a water bath, I approximate that I used 4 oz. of soap in 64 oz. of water.