Article: Start simple for now, as complex molds are much harder to keep together at first. Get a piece of modeling wax and use a precision knife, Dremel, and any other tool needed to make a model of your jewelry. Whatever shape you make now will be the shape of your finished piece.  You are making an exact replica of your eventual jewelry. Using a piece of jewelry you like as a model will help you design better pieces when you first start. Using some more wax, craft several long, wires out of wax and attach them to the model so that they all lead away from the piece. This is easier to understand when you see the whole process -- this wax will be covered in plaster, then melted out to make a hollow version of your shape. You then fill in the hollow part with silver. f you don't make sprues, the melted wax can't actually get out and make a hollow area.  For smaller pieces, like a ring, you may only need one sprue. Larger pieces, like belt buckles, may need up to ten. All the sprues should meet at the same place. They will need to be attached to a sprue base. The sprues all meet together, and you attach the mold to the sprue base where all the sprues meet. This allows the wax to melt through the bottom of the base and leave the mold. The flask is a big cylinder that slides on top of the sprue base.

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Carve a piece of hard modeling wax into your desired shape. Attach 3-4 "sprues," wax wires that will provide a channel for the wax to melt out later. Attach the mold to the sprue base using a bit of melted rubber. Put the flask on top of the sprue base, making sure you have a quarter inch between the wall of the flask and the model.