Cuttlebone is the remnants of a cuttlefish. This ancient method of silver casting is relatively easy to produce without specialized tools.

Step 1: Materials

Cuttlebone - These are used for pet supplements, you can find them in a moderately sized pet store. This 2 pack cost around $2.

Sterling Silver - This can be scrap or casting grain.

Flux - borax powder

Step 2: Tools

Crucible - used to melt the silver

Torch - I used an acetylene torch. The torch needs to heat the silver to melting temperature, over 1783 F.

Graphite rod - used to stir the silver and ensure it is fully melted.

Fire Bricks

Stylus

Fine Paint Brush

Steel Wire - for registration pins and binding wire.

Jewelers saw

Files

Sandpaper

Rotary tool - Dremel

Safety Gear

Gloves

Flash Goggles

Step 3: Prep the Mold

Cuttlebone has a dense shell on one side and the interior is filled with a compressed talc like powder. This powder is calcium rich and used as a dietary supplement for various pets. These bones are brittle, you need to take care and not use too much force as they can crumble before your eyes. By rubbing the two halves together you can create a flat surface between the two halves.

You will then need to cut one end on both halves to create a flat surface where you will eventually pour you molten silver.

Step 4: Creating the Void Within the Mold

This is where you get to be creative with you design, but there are a few considerations. Cuttlebone has layers like a tree, this is what I love about using this for casting. These striations create a beautiful piece. With the two halves and the softness of the material you can easily get a ridge between the mold halves. With this in mind lets begin to create a ring.

I used a plastic ring sizer to get an idea of how big I needed to carve out. I started on one halve with only a stylus to carve into the cuttlebone. You will need to take care as the material is very soft. As you are carving you will need to softly blow out the powder that is created. Once you have something you like, take a small soft paint brush and gently brush into the ridges. This will loosen the powder remaining and create a contrast between layers.

Satisfied with the first halve, its time to move onto the second. I used powdered chalk on the ring sizer and put it over the carving. I them lowered the second piece over it. Once released the red chalk left a ring on the blank face. This is then carved in the same manner.

Step 5: Mating the Two Halves

Now that we have 2 halves we need to create a way to line them up. i cut 3 pieces of steel wire approximately 1/2" long. These are then placed into one side of the mold, don't put them directly in line with the flat portion we cut off. Line up the halves and close them together. This will make sure you can take the mold apart and put it together so that the halves up easily. Additionally this will keep the halves from sliding when you bind them together. This step can be done prior to starting carving to make sure both sides align.

Step 6: Carving the Sprue and Vent Channels

You will need to create a way for the molten silver to enter the mold and a way for hot gases to escape. First carve a line from the flat portion we cut at the beginning to you mold cavity. This is where the silver will enter the mold. Create a funnel shape at the top of the mold to assist in poring. Add vent channels off of the main cavity for gases to escape. Blow out all of the loose dust from within the cavity and channels.

Step 7: Bind the Halves Together

Using the binding wire, bind the mold halves together tightly. Your mold in now ready for casting.

Step 8: Ready for Melting

This is my work station ready for me to begin melting the silver and ultimately casting. A word on safety. Flash googles or glasses are used to protect your eyes, as staring at the flame and molten metal can burn your retina like staring at a welder. Gloves are a good idea to protect you hands and arms, I use welding gloves. A bucket of water. Your dealing with fire, if something catches on fire your ready. Clothing, long pants and boots. you don't want to wear sandals and have a drop of molten metal land on your toe. Make sure your tanks and lines are in good working order. Follow the manufactures recommendations on operation.

Put all the silver in the crucible and add a pinch or two of flux into it. Put on your gear and start the fire.

Step 9: Melt and Pour

Heat you silver until it is melted. It will look like a puddle of mercury inside your crucible. You will want to pour the silver into the funnel at the top of your mold. Continue adding heat as you pour. Pour in a single fluid motion, trying not to stop the flow of metal. Once you see the sprue fill with metal any excess in the crucible can be poured into the water and recovered for later. Watch the Pouring. Let the metal cool before undoing the binding wire.Check out my cooling sprue.

Step 10: The Big Reveal

Removing the binding wire you will see your new ring within. Be careful as the silver may still be hot. With gloved hands pick up the outside of the mold that the piece is in and drop it into the water to cool.

Step 11: Remove the Sprue and Vent Pieces

You will need to saw the sprue and vent remnants off. Save these for your next ring cast.

Step 12: File and Sand

Using a file remove the larger ridges and rough spots. You can shape the ring somewhat by removing silver, but you will sand away the cuttlebone detail. Pay attention to the interior of the ring, this needs to be smooth. Start with a rough grit and continue working the rough edges and interior. Once you have gotten everything smooth it is time to polish the ring. When you have finished polishing you may notice some dark spots in the creases. This is usually powder from sandpaper or rouge. Wash your ring in warm water with some dish soap and an old toothbrush.

Step 13: Conclusion

Most of the steps are easy, heating until the silver is molten requires a hot flame. A crucible can be found on Amazon for a reasonable price. The rest of the tools are fairly common. A jewelers saw can be substituted for a hack saw. Silver can be substituted from bronze. A Reenactor or Cosplayer can create a ring or even a belt buckle by using this method. This ring may not rule them all, but maybe this contest. Please up vote!