I filled the claw mold with plaster-of-paris. The plaster shrinks a tiny bit, causing visible damage, which I will have to find a way to correct without further ruining the plaster. What I learned from making the rock display base is that when new plaster makes contact with cured plaster, it solidifies instantaneously. It's extremely weird. It doesn't solidify to a rock-like hardness like fully cured plaster; but it solidifies to the consistency of a cookie. The only way to stifle this reaction is to add extra water to the new mix of plaster before introducing it to the cured plaster. Another idea I might try is to apply plaster powder to the claw's blemishes, and then spray water onto that. The recommended mix ratio (2 parts plaster, to 1 part water) will be thrown way off, but it's worth a try. Anyway, the plaster casting only needs minor corrections.
The reason I made a plaster casting is because I am now going to make a heavily weathered and fossilized version of the claw. What you've seen up to this point is what I like to refer to as a poached claw - a claw that has been taken from a recently dead raptor. Plaster accepts cracks and scratches very easily, and with its mineral properties the artfully applied weathering will closely resemble a real fossil. I am going to scuff it up, add hundreds of pores, and I am actually going to break it in several places, round-over the edges of the fractures, and then glue the claw back together to create authentic cracks, but which won't affect the integrity of the final resin castings. So that also means I'm going to mold the plaster claw.
Here's the plaster claw without any of the aforementioned work done to it yet.
Here's a projection of how and where I intend to add weathering to the claw.
There is science to the blemishes.
Yellow = This section was covered in a keratin sheath while the animal was alive. This is also the part that dries up first after death. Cracks form along the natural growth lines of the bone, which is why the yellow lines follow a somewhat uniform path.
Red = The denser part of the red is where the flesh of the toe meets the keratin of the claw. Everything in the red area and behind it was covered in flesh while the animal was alive. This means it was also soaked in fluids, and attracts the most bacteria. The bacteria eats into this section of the bone, leaving a lot of deep pits.
Blue = These areas are called tendon anchoring points. Tendons attached into large pores in these areas. The pores become larger as the bone dries, and as bacteria finds its way inside.
Green = A large cartilage pad used to be on this part. Cartilage is a soft, moist tissue which attracts bacteria, so this area will also be heavily pitted.
Purple = A rough idea of what the cracks might look like.
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Side note: I will also be making a poached claw that has a keratin sheath. I made one a few years ago, but it wasn't as accurate as I would like.