My school has this jewellery casting workshop on Saturday. The jewellery is cast from cuttlefish bones.
Here is how we do it.
Trim off the edges of the bones as they curl inwards.
Cuttlefish bone has a contour. Locate the highest point and saw the bone into 2 pieces.
Sand the bones in circular motion to achieve a fair bit of flat surface.
Find yourself a small object to cast the mold.
As cuttlefish bone is really soft, you can pressing your object in. If it doesn’t leave enough impression (depth), do carve a little of the material out. I’ve to slit small lines so that the molten silver can reach the tiny detailed ends.
As I am doing a single side casting, I’ll just need to brush the other piece of bone with dry brushes to create air vents. Jewelleries with such wavy patterns denote that they are cast from cuttlefish bones.
Cut openings on both sides to allow molten silver to flow in. Secure the mold with masking tape.
The torching equipments.
Secure your mold.
Torch the silver in ceramic bowl.
Pour the molten silver into the mold’s opening. Keep the mold upright.
Observe the mold through the red button. The mold is ready to take it apart only when the button turns grey.
The button has turned grey but it’s still hot. Remove the mold and cool it in water.
My burnt mold. Only for 1 time casting.
Saw away the excess and button.
My casting before restoring the shines.
Casting back, that wavy lines by the air vents.
My casting weighs 2.8 grams. And I’ve to pay for the material used.
Shiny silver after a water bathe in alum (alkaline).
It isn’t an easy process actually, very much of these are assisted by the instructors who are present. Especially when designing the cast, you’ll need to plan. One of the considerations to make design feasible is to consider if the molten silver can flow into the corners and turns. After all, the molten silver is not like the runny water, it’s much thicker.