Blog Joalharia Tutorials

Cuttlefish bone casting

Cuttlefish bone is made from a soft material that’s easy to carve, it has an interesting texture and can withstand the high temperature of molten metal.

Cuttlefish bone casting allows you to create metal pieces with a unique texture without any specific tools apart from a torch that can reach the necessary temperature to keep the metal in liquid form during the process.

Preparing the cuttlefish bone

You must choose a cuttlefish bone that is large enough to be cut in half. The smaller ones don’t have enough material to cut and carve.

From this point on, I recommend the use of a dust mask while handling the cuttlefish bone.

You start by cutting off both pointy ends and a bit from the sides as well, to achieve a rectangular shape.

Then you saw the bone into two equal halves. All the cutting is done with a jeweller’s saw.

Placing a 600 grit sheet of sandpaper on the table, you now need to sand down the inside of each half to smooth them out and remove any saw marks.

You can use a paintbrush to remove loose dust, bringing out the texture. and then put aside one of the halves for later.

Plan what you want to carve onto the other half. I used a coin to mark a couple of circles on this one. You can use a needle, a file or a small knife to mark the lines and carve into the cuttlefish bone. The bone has a texture similar to styrofoam and is easily carved. I continued using a knife, files and sandpaper to perfect the shape.

Because I had two separate circles, I carved a large channel between them so the metal could flow down freely and fill the entire shape.

Out of the lower circle I carved some thin channels leading to the top, so the air could escape when I poured the metal. This is an important step to ensure the metal fill the whole shape.

After carving the desired shape, you still need to carve a sort of funnel at the top where you plan to pour, so the metal has a big opening and touches less material as it flows. This prevents the metal from cooling too fast before it reaches the bottom of the shape.
This funnel should be done on both halves of the cuttlefish bone but is more important on the carved side.

The final step is to join both halves and secure them with binding wire.
The cuttlefish bone must then be held steadily either on a vice or between two soldering blocks, with the opening (where you carved the funnel) facing up. Either way, make sure to protect your table, under the bone, with either a steel sheet or a soldering surface because the metal can sometimes overflow.


Melt your metal on a crucible with a torch. A gas/oxygen torch is a good option because it can melt the metal quickly and keep it at the right temperature while pouring.
Carefully but quickly, pour the molten metal into the cuttlefish bone, making sure to stop once the funnel starts to fill.

Let it cool for a bit or immerse it in cold water. Remove the binding wire and check your casting.
The cuttlefish bone gets burned during casting, so if it didn’t turn out well you must repeat the whole process again with a new one.

Good luck and above all, have fun.

I leave you with some pictures of jewellery I’ve made with cuttlefish bone casting. Enjoy!

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