Casting the Carter Bog Megalonyx, Part 3

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We’re continuing to work on molds of the Carter Bog Megalonyx. While we haven’t produced any new casts in the last week, the molds are progressing rapidly.

The most complex piece we’re working on at the moment is the lower jaw. As I mentioned in Part 2, because of the jaw’s complex shape we’re doing this one as a 3-part mold. Two of the parts will cover the lateral and occlusal sides of each dentary, while the third part will cover the medial sides and the back of the mandibular symphysis. Last week we did the first silicone pour on the first side, and today we added a second coat of silicone (above). This side will need at least one more layer of silicone.

Last week we also started pouring one of the ungals, the bone that supports the claw on the toe. Is is a 2-part mold, and we completed the first side on Friday. This morning we flipped it over:

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After spraying on a mold-release compound, we started pouring the second side:

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We also began working on the cranium. This will also be a 2-part mold, and we started with the more complex, ventral side. We started by building up a clay platform around the bone:

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Eventually we completed the platform and seal it up against the bone, with clay walls around the edges to hold in the silicone. We also added in a clay rope to align the two halves of the mold and provide a seal when we pour resin into it, pour spouts (at the occipital condyles, on the left) and vent lines to prevent air bubbles (below):

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Finally, after spraying on mold release, we poured the first layer of silicone:

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With a little luck, the ungal and cranium might be completed by next week. I think the mandible will take a bit longer, since we’re still on the first part.

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