Cuttlefish are amazing things. (my Pinterest Board on Cuttlefish) They are molluscs, from the same class as squid and octopus and they are masters of disguise, able to change their shape and colour in order to hide. Wikipedia
The cuttlebone, pictured here, is an internal structure which aids bouyancy. They wash up on shores all around the world. They are used to give caged birds the calcium they require. And, more excitingly, they are satisfyingly carvable into moulds for metal casting.
I started by cutting the cuttlefish bone in half. It cuts easily but you have to take care to keep it straight and as smooth as possible, then I pressed my legoman template into the cuttlebone and started carving, including the channel where you pour the molten silver and channels for air to escape. Then I bound the two halves together with wire, propped it up in a bucket of sand and took it outside (because I was bit scared about setting the house on fire!)
I put some of the little offcuts of silver I've gathered over the years into the crucible and turned the kiln on. The silver was soon in a molten state and, after donning safety goggles, gloves and apron (probably unneccessary but I'm a scaredy cat and anyway better safe than sorry!) I poured the silver into the mould. Couldn't believe how quickly it returned from its glowing red liquid state to a solid.
It was exciting to take the two halves of the cuttlebone mould apart - they are ruined by the process as they burn - but there is the cast piece. Wow! I had to do this twice obviously and it was impossible to get them identical but that's part of the charm.
After a lot of polishing - the process that always takes the longest - and fashioning two tiny black bow ties they looked great. My son was delighted and so was Dad! Although they're so precious to him that he doesn't dare wear them!