Liquid rtv molding silicone

1.Prepare a hollow lion head which is treated as mother model.
2.Center lion head on a piece of board.
3.Fill the hollow space of lion head with clay, leaving no void.
4.Insert two bolts in the clay.
5.Blend two parts of liquid rtv molding silicone thoroughly.
6.Deair all the bubbles in the molding silicone mixture with vacuum pumping tool.
7.Coat the first silicone layer on the surface of lion head and some board area surrounding the lion head. This silicone layer must be very thin and even in order to expel all the possible bubbles.
8.When liquid rtv molding silicone rubber gets cured, coat the second layer of rtv molding silicone on the surface of lion head, as well as appropriate surrounding board area.
9.Wait for curing of liquid rtv molding silicone. When time is up, coat the third layer of rtv silicone.
10.The fourth layer of liquid molding silicone is applied as the same way as the finished first three layers.
11.Use nipper pliers to remove the bolts.
12.Spray some release agents on the surface of another two machine bolts(about 5 inch).
13.Plug the two machine bolts in the holes left on the surface.
14.Fill the mouth of lion head with resin.
15.Use clay to divide original model into two equal parts. The model parting line goes through the middle position of lion mouth.
16.Additional clay is needed to reinforce the main model parting line. The pair of machine bolts should also be encased by clay.
17.Spray release agent onto surface of clay area.
18.Make the first half outer resin mold. When it cures, make the second half outer resin mold.
19.Drill several screws through the parting line edge for easy reassembling.
20.Take out clay from the cavity. Spray release agents on the inner surface and machine bolts.
21.Thread a nut halfway of each bolt.
22.Drill several screws to fix a wooden chip traversing the bottom of the total mold.
23.Pour resin into the cavity.
24.Remove the two machine bolts.
25.Remove the resin lump from the cavity(the function of wooden chip reflect here).
26.Demold the outer shell.
27.Remove the resin lump in the lion mouth.
28.Demold rtv silicone mold.
29.Place the smaller resin lump back in the lion mouth.
30.Seat the rtv silicone mold in the outer shell.
31.Plug the first two bolts back in the two holes.
32.Reassemble the outer shell.
33.Place the bigger resin lump back in the cavity(it should be sprayed release agent before). The holes on the resin lump should aim at the holes of the liquid rtv silicone mold.
34.Tighten the bolts.
35.The liquid rtv silicone mold is ready for casting.