Scratch building is the first step into a bigger world. You've just made your own gauntlets/armor/blaster using the awesome templates provided by TDH members. And now you're thinking: I'd love to be able to make copies of this!
There are some terms you'll see regularly on the board.
Slush casting is essentially a manual version of rotocasting.
A hollow mold has a small amount of resin (usually quick setting) poured in and is rotated by hand to ensure that the entire inside surface is coated. Often several coats are required to get an adequate and even thickness.
"Casting liquid is poured into a mold and then automatically turned in two opposing directions which smoothly distributes the casting medium." -plastermaster.com
Mother Mold / Mold Jacket
A rigid outer shell used to hold a flexible rubber mold in place while casting.
There are tons of references online describing in great detail how to do this stuff. So many in fact that it becomes seriously overwhelming!
Here are a few references to get you started:
evan4218's list of molding and casting suppliers[*]Reynolds Advanced Materials Howto Guide[*]Smoothon's Youtube Library[*]TIM ALLEN's Fiberglass 101 video[*]SEEKER's guide to heat forming armor WITHOUT a vac table