1 - Begin with an original finger coral model.

2 - A rigid piece of clear acrylic is used as a mounting board.

3 - Since the coral model is not free standing, a base needs to be created out of non-sulfur based modeling clay. The clay base will stabilize and balance the model during mold making process.

4 - An oval pancake shape, proportional in size to the coral model, is created out of clay and pressed securely onto the acrylic board.

5 - The coral model is centered and embedded into the modeling clay.

6 - Add texture to the clay base using a broken popsicle stick. Texture in clay base can be made to match texture in finger coral.

7 - Liquid mold rubber will be poured over this model and allowed to cure as a solid block of rubber. Once the rubber cures, the original model is extracted by cutting the block of rubber using a razor knife. The cut line must be marked on the model before pouring rubber.

8 - Use a Sharpie permanent marker to draw a parting line on the original where you intend to cut the mold when it is time to demold the original.

9 - Since the original has a lot of detail, a soap-based release agent will get into the crevices better. Combine 2 parts isopropyl alcohol and 1 part dish washing soap.

10 - Mix the alcohol and soap together until blended thoroughly.Stipple the release agent into the detail of the original model. Let dry a minimum of 30 minutes.

11 - Use a brush to lightly stipple the agent to the surface of the original.

12 - Acrylic is used to build the mold box. Position mold box sides so that the walls are at least ½ inch (1 cm) away from outer most points of the coral model. Leave 1/2 inch (1 cm) clearance over the highest point of the model.

13 - Hot glue the edges of the mold walls to the base board.

14 - Be sure the walls are completely sealed to prevent the silicone from leaking out of the seams.

15 - Continue hot gluing until all the walls are built.

16 - Use a mold strap reinforce glue line and hold all mold walls together.

17 - Sealed, strapped and ready for the mold rubber to be poured.

18 - Mold Star 15 is used to make the mold. It is mixed 1 part A to 1 part B by volume.

19 - Dispense part A.

20 - Dispense an equal part of B.

21 - Combine both parts A and B into a larger mixing container and mix thoroughly until there are no color streaks.

22 - Mold Star 15 has a pot life of 50 minutes. It does not need to be vacuum degassed.

23 - Pour the rubber into the lowest part of the mold box in a long, thin stream.

24 - Pour rubber in a single spot and let it rise over the model, finding its own level.

25 - After the rubber cures for 4 hours, remove the mold walls.

26 - Lift the entire mold to separate it from the base.

27 - Remove clay base.

28 - You will need to cut your mold open in several areas in order to demold your original piece. It is helpful to have a friend help hold the mold open while cutting. Follow the guide lines that you drew on the original model.

29 - You will need to cut in between each finger to allow for an easier demold.

30 - Continue cutting just enough so that you can demold your original.

31 - The mold captured all the detail from the original model.

32 - For rigid support, place 2 of the molds walls on either side of the mold, pressing the seams together tightly.

33 - Strap the acrylic mold walls to hold the mold together tightly with even pressure. The mold is now ready for casting.

34 - Smooth-Cast 325 COLORMATCH urethane resin and Ignite fluorescent color pigments are used to make the casting.

35 - Dispense part A.

36 - Dispense an equal part of B.

37 - Pre-mix the Ignite orange pigment.

38 - Mix the Ignite orange into part B until there are no color streaks.

39 - Transfer pigmented part B into a larger mixing container. Pour part A into part B.

40 - Thoroughly mix parts A and B together for 90 seconds. Smooth-Cast 325 has a 2.5 minute pot life.

41 - Pour resin into mold cavity.

42 - Let cure for at least 20 minutes.

43 - Remove the mold strap and acrylic mold walls.

44 - Mold Star 15 has good tear strength and easily flexes open.

45 - Slowly pull and wiggle your casting out of the mold.

46 - Demolded casting is an exact replica of the original.

47 - Placing the finger coral casting in the aquarium. The base that was created stabilizes the casting.

48 - The realistic finger coral glows under fluorescent light and is a beautiful addition to your aquascape.

49 - Coral castings with varying amounts of Ignite and SO-Strong pigments.

50 - Coral castings under UV (black) light.

51 - View our other videos and galleries to learn how you can create a variety of sea creatures for your aquarium. The possibilities are endless!