The inner-arm portion of the bracers have been cast. Since there were some issues with the first casting of the outer bracer, this is really the first time I got to see what happens when it works.
In the first few pictures, notice the "pits" in the silicone (white) mold part. Those are the keying points, to help the molds line up. This really helps, because the silicone molds are pretty flexible. The clay hunk at the end of the mold is there to create a pour spout void.
When I cast the previous part, the outer bracer shell, the mold leaked, and this casting material isn't cheap. So this time, the silicone impression mold (inside the hard outer mother mold) has a thin garbage bag carefully placed around it. You have to be cautious to not get much bunching, or otherwise cause undue thickness between the silicone and mother molds, or you will distort the casting. The extra garbage bag that stuck out was just folded over the whole mold, once the mold was assembled. The large rubber bands just hold everything together.
The castings look VERY nice. Switching to the silicone impression mold was a good move. It retains so much detail, that you can actually see cast fingerprints in the castings, that were present on the original clay model. I pigmented the urethane black(-ish). You'll notice on the right side of the image where I'm holding the casting, that the casting has some bubbles in it. I think this "foaming" is because of the sand-like filler material I added to the urethane. I'm not sure yet how to avoid this. It does weaken the part where the foam is, but the foam only occurred at the part of the mold that was highest (the foam floated up). I've verified (in future castings, of the finger armor) that if I don't add the filler, the foaming doesn't occur.