Introduction to wax carving and lost wax casting
Lost wax casting is an ancient technique used to produce one-of-a-kind metal sculptures. You can even find a small exhibit about it at the Royal Ontario Museum.
The Koi Fish ring is one of my first and favourite designs made using this method. It is essentially a tiny piece of sculpture, handcarved from jeweller's wax and cast in precious metal. Below, you can see my wax model before casting (on the left), and the finished gold ring beside it.
Wax carving tools
Wax carving tools are essentially anything sharp that can be used to cut and shape jeweller's wax. Many of the tools are the same as those used in woodworking, printmaking, and dentistry!
My favourite tools are a tiny flat chisel, a craft knife, and a rotary machine called a micromotor, which works with different types of burrs or drill bits. I use a green jeweller's wax, which feels a bit like candle wax, but firmer and specifically formulated to hold carved detail. For this project in particular, I'm using a green wax tube that has a convenient cutout for making rings.
Jewellery design
I have always loved the movement of koi fish, especially butterfly koi, which have ever-growing fins. For this ring, I made quick line sketches until I found a shape that I liked:
Wax carving process
Working with a chunk of the green wax tube, I use the rotary tool to burr out the rough lines from my sketch. At this point, it looks more like napa cabbage than a fish 🥬
I carve the fish fins separately and try to attach them to the main body with molten wax, breaking the the ring band in the process. This often happens when I start adding detail to the wax model — it becomes more fragile to work with.
Ignoring the missing band for now, I attach the fins and continue to smooth out the surface of the wax. Refining the wax surface prevents dents and scratches from being included in the final model, and also reduces the chance of porosity (little air bubbles, or holes) that can appear during casting.
I carve a new ring band and reattach it to the main body with molten wax. To melt wax, I use battery-operated heat pen with a thin wire tip. I adjust the position of the fins and ring band by melting and re-positioning them as needed.
Casting the wax model
I take the wax model to my local caster, where they put the wax model in plaster. Once hardened, molten gold is poured into the plaster, replacing the wax model inside. The whole thing is cooled, broken apart, and the gold casting is retrieved.
I don't have photos of this part as it happens in my caster's workshop, so I drew a quick diagram for you instead :)
Polishing gold jewellery
To finish the gold casting, I use my rotary tool to apply different types of polishing compound. The polishing process creates very tiny micro-scratches on the metal surface that appear as lustre or sparkle. To bring out the flourish and movement of the fins, I add extra handcut texture using a diamond tool.
My favourite detail is the way the lines flow through to the inside of the ring:
More about lost wax jewellery
The lost wax process is my favourite technique because I can be both freeform and precise. In my work you'll find natural shapes and delicate lines, carved down to the very last millimetre of detail that I can get the tip of my knife into!
If you're interested in learning more about lost wax jewellery:
Thanks for reading!