I thought I would chart the process of making a simple ring using the casting process, there are many ways of making an item of jewellery, casting can be a useful technique and in this case it is used for making a one off piece, but it is most often used for making multiples of a item. You can make a master model in a base metal such as copper or brass and then cast it into silver or gold, but in this case I started off with a wax model as carving a master in wax allows for less wastage of precious metal and also allows for shapes and textures which would be more time consuming and difficult to create by other means.
This bock of wax comes with a hole to start you off sizing the ring to your requirements. Firstly a block larger than the design requirements is cut off using a jewellers saw fitted with a special spiral blade which can cut though the wax without clogging too much.
The outline of the design is carved into the wax, and the hole enlarged to the ring size needed, in this case I was making a men’s ring for a very large finger!
The block is cut down to slightly larger than required so it can be filed into shape later and the detail starts to be cut or carved into it.
Although the weight of wax is substantially lighter than the metal you will find that taking away as much of the wax as possible will keep the weight down and also save money! In this design inside the front of the ring was hollowed out so it would be more comfortable to wear due to its large size.
The wax model is then sent off to the casters, who, by using the lost wax casting process, will produce the design in whichever metal you have asked for, in this case silver.
In the lost wax casting process the wax model is mounted on a wax rod called a sprue and this is then mounted onto a ‘tree’ with other sprues, the central rod is secured into the base, and filled with a watertight section of pipe called a flask. A plaster like material is poured into the flask after it has set the base support is removed, the flask it placed into a kiln and the wax tree is melted away, leaving a negative space of the shape, molten metal is poured into the shapes, the plaster dissolves when the metal is quenched leaving the finished shape.
The casting comes back in a rough unfinished state, so then the next task is to clean up the piece file back the excess metal which was used in securing the original model to the tree. Once the piece if filed back, it can then be polished to the required finish, shiny or matt.
In this design, I then used an oxidising solution, which turns silver black in colour on contact, in order to emphasise the carved line detail on the sides and top to give the piece contrast and depth.
With the ring finished, it just has one more leg of its journey left, travelling to its new owner!