I was amazed to see how much of the detail the molds had captured. The mold was stuck and bonded to the Freeman cast pretty well, as it is very pitted. I slowly worked it off and the originals were just fine. I let them cure at room temperature for another day before I tried making my first replica copies.

I found that with about a half inch or of extra silicone border around the mold edges, they appeared rather sturdy. (Fig. 5)

Figure 5. The completed silicone mold.

You can use various products to cast casts, but I would not recommend plaster of paris. Instead, I would suggest using Dentastone, Hydrostone, Hydrocal B-11, or Ultracal 30. Dental supply companies carry this product, and most sell it in 100 lb. bags for around thirty-five dollars. It is actually cheaper than plaster anyway, and much harder, plus you can soak the casts in water if need be without them getting mushy.

I mixed the Hydrocal to proper consistency, and poured half of it in the molds. I vibrated them the same way to remove any bubbles, and let that set up for about five minutes. I then mixed and poured the remainder of the Hydrocal, filling the mold. A little more vibrating and they were level with the top of the molds. (Fig. 6)

Figure 6. Filling the mold with Hydrocal.