Modeling, Molding, and Casting Question

[brims]

I have to make a somewhat simple cast out of silicone to seal an akward gap in the bed of my truck. I have been trying to figure out the right materials to use. I need to make a beginning model out of something easy to sculpt, then make a mold out of that with something, then make a casting of that mold with silicone rubber as the final medium.

What mediums should I use for the initial model and the mold. I was thinking wax for the initial model, not sure what to use for the mold. Any advice would be appreciated. Thanks in advance.

[Pilot Dane]

I make my molds out of modeling clay. Just the normal modeling clay that does not dry (oil based). Then I mask off the surrounding area. Coat the clay and several inches around with a release agent (vaseline) and make my negative mold out of fiberglass.

[brims]

That should get me on the right track, thanks.

[Gmavin]

Been a Artist and studied many things as bed liners and painte over 60.(1)can not paint over silicone use aelastomeric latex sealant. (2) mold with plaster of paris. (3) a release agent should be used, but if not available, use warm wax or rub mold down with such.Hope this works for you personaly I like to see prodject, sure seems you could fiberglass it.