Theres only two ways of silicone molding i know of right now.
im new and all, but from what i read (from Gene) you can do it real cheap by buying ge silver brand 100% silicone caulking. but it takes like a week. i just guess you could use the same way of doing it for armor or whatever. you just have to sand it down when your done. he said this for making a bio:
you need 7-10 tubes of silver brand ge 100% silicone caulking (avail home depot) one roll of plasterers seam tape (mesh tape for drywall seam reinforcement) can of krylon clear coat, water spray bottle, latex gloves, and a caulking gun. 1: gather materials 2: prepare the sculpt. take the krylon and seal the clay. you dont want sulphur with silicone. seal it good with a couple of coats.take a tube of silicone and insert it into the caulking gun. cut the tip off near the body of the tube so you have a wide opening. puncture the seal inside the tubes stem. start squeezing the silicone onto the sculpture squeeze it onto the sculpture and rub it with your gloves on around the sculpt. make sure there arent any air bubbles. dont worry about not making it thick cause this is the detail coat. once the detail coat is done you want to wait for it to dry. you can use a water bottle to spray it with to speed up the drying process. silicone dries by having a reaction with water in the air. oh yeah. you dont want it more than a quarter inch thick or it wont dry. repeat the step of applying silicone until you get it about a quarter inch thick. you could put another coat on after that. then take the plasterers seam tape and cut some strips of it and take and put a thin layer of silicone on what you have so far. press the tape onto the silicone and cover the entire surface with it. itll reinforce the silicone and keep it from tearing. then you can add another layer of silicone. the water spray helps it dry faster. his tutorial said however thick you want it is up to you and this is a cheaper way to do it than buying something like rtv silicone. remember this was originally meant for doing a bio.
if youre looking to do something else theres a silicone molding tutorial in the huntorials section in the thread called silicone molding tutorial by carlart.
If you use the silicone tube caulk method you can speed up the cure time by adding acrylic paint to it. I used the cheap craft paints that are like $.50 a bottle. mix it like you would Bondo. A layer of this mix will cure in less than a half hour. Also I bought the clear silicone made by Mainstays from Walmart and it was $2.14 a tube and it worked great.
If you are wanting pourable silicone or a better quality brush on check out Smooth-on.com