Monday night, my friend Sassy_fae accompanied me to class both for the company and because I asked her to take some photos of me in the process of making a pendant. Some folk here had expressed some interest in how this was done. This then is for the curious.  

I chose to do this one in cuttle bone. Cuttle bone is the bone from the inside of a cuttlefish, which is a squidlike critter. The cuttlebone is a porous internal shell that helps control buoyancy, making it functionally similar to swim bladders in fish.

When I was a kid, my mum and I went to England and while on the shores of the Isle of Wight I remember seeing cuttle bones on the beach. Being a cute kid back then and customs having a bit more of a lax attitude for organic material, I was able to bring home several cuttlebones from that trip. I'm sure they eventually got fed to a budgie, but it was pretty cool to be where they washed ashore.

So, I started out with a whole cuttlebone.
 

The cuttle bone is cut in half and the soft side sanded flat so the two halves fit together face to face.


I happened to forget my sketch book and the drawing I was using as a guide so I had to use the last partial pendant I did as a guide. I was getting pretty good at carving this thing by this point, but I still didn't want to screw up, so I just took measurements again.


And then using the stencil as a guide, I started carving into the bone.


The carving is starting to take shape here.


Once the carving was complete I carved the sprue hole through which the molten silver would be poured. Sterling silver shot was weighed and put into a crucible.
 

An oxy-acetylene torch was used to melt the silver. I used a steel wire to bind the two halves of the mould together. The metal was melted and poured into the mould. Once the metal cools a bit and solidifies, the wire is cut away and the piece is quenched in water.


The process destroys the mould so these pieces are nominally one of a kind. There are methods to reproduce a piece, but the school doesn't have the equipment to do this and I kind of like the idea currently of people having one of a kind pieces.

The piece is then placed in an acid bath called 'ickle'. It is a powder called sparex mixed into water and then heated in a crock pot. I think the technical term for this pickle is aquaregia. The lab I work for makes this as a reagent, a mix of hydrochloric and nitric acid. The stuff we use in class is dilute, but it gets the casting skin, carbon and fire scale off the pieces quite nicely.


After a few minutes in the pickle, the worst of the casting skin is off and it can be buffed. A flat shiny piece would normally go through several grits of paper, then a rough grit in grease called tripoli on a buff, and then a fine grit in grease called rouge on a buff to bring up the fine shine that is seen on most jewellery. But with cuttlefish casting, I can just use a wire wheel and it's decently shiny and doesn't take down the texture that the cuttlefish gives to the piece.


As you can see, there's a big knob of silver on the top of the newly cast piece. That's called a button. We like to see a button when a casting is done. It means several things, but most importantly that the amount of silver was gauged correctly and that there were no breaks in the mold to let the silver out. The piece on the right would have worked, if I'd gauged the amount of silver better. So, the knob needs to come off so a hole can be made where a link or bail can be placed through which a chain can be strung. As Jenn pointed out, I can actually say 'I'm sawing the knob' and actually literally mean that rather than euphemistically. Apparently I look a little crazed when I'm doing my silver work.


Once the main part of the knob is removed I can start refining the shape of the bail with a file. And then drill a hole. Silver smithing has a lot of equipment that sounds sexier than it really is. One of the most used tool in the shop is the Foredom Flexshaft.


Et voila...a hole!


And let it be known, that I put my blood into my art, it means that much to me. Wound sustained removing a very sharp drill bit from the flexshaft.



And it's always nice to see if the gem fits the spot that I carved to hold it. The stone was a bit wobbly but that's easy to fix by deepening the hole it would sit in and shaping it to the back of the stone.


I thought I would have time to set the stone, so I went ahead and started drilling the holes for the wire used for the setting. I could have used a pre made setting, but that would have held the stone above the face of the tree and I wanted it somewhat flush. So I cut some 1mm wire, sanded the ends, used a centre punch to start the holes so I could drill into the face of the piece to set the wires.


Once the wires were in place, I fluxed the entire piece. Flux is used to prevent fire scale (oxidation) of the larger piece and also as a wetting agent to break the surface temperature of the metal used as solder and thus help the solder flow into the joins by capillary action. This time I used a large propane torch (with ambient oxygen intake) to heat the metal and solder the wires into place.


Here you can see the beads of solder that will flow down the wire to join the wire to the main piece.



The pickling process is done again and here is the piece ready to have the stone set. I actually messed up two of the prongs and set them too close to the centre so the stone wouldn't sit flat, allowing the prongs to be bent over to hold the stone in place. I'll cut them off, drill two new holes and try again next week. Then I'll put on a bail and the piece will be done.


Incidentally, this piece looks so bright right now because the surface is covered in fine silver. Every time the 925 silver is heated, molecules of pure silver come to the surface, making a pearly white finish. I used this method when I made a hawk pendant and it looked pretty nifty. I'm not sure whether I'll patina this piece or leave the bright shiny fine silver on the surface.

So there you go. I'll post pics of the finished piece next week.