a necklace

This is last of my project for the silversmithing class - a necklace that incorporates the finding (clasp) into the design.

lost wax casting process, part 2

After all the wax is melted out of the flask, it is put in a casting machine that pulls a vacuum through the plaster and helps pull the molten silver out to the edges of the cavities left by the wax.

Here is the same tree, now cast in silver.

It was pretty tricky cutting all the sprues off from the inside of the piece. Luckily the blade of a jeweler's saw can be threaded through holes and then attached to the saw frame.

And this is the final piece all polished up. The project was called the Volume Challenge - the piece had to weigh less than 1 gram in wax and not fit in any of the given boxes. I think this one passed the challenge. It was definitely big enough. The wax weighed 1.6 grams when I cast it, but then I did a lot of filing and sanding to the silver.

lost wax casting process

Here are some snapshots of the long process I went through for one of my silversmithing projects.

First I turned a hunk of machinable wax down into an elipsoid using the radius cutter on a lathe. The photo above shows a piece of acrylic being turned, but the setup was the same for the wax.

Here is the wax after turning and additional drilling using the drill press. The large central hole was used to hold the wax onto the aluminum lathe fixture.

I used an X-acto knife, small carving tools, and the Foredom flexishaft with different sized burrs for carving out the inside.

It broke a couple times, and I melted the tiny pieces back together.

The I sprued the carved wax onto a wax "tree" with a couple of other parts that I carved for a necklace project. The rubber base that you see here fits around a metal cylindrical flask that gets filled with plaster. The plaster hardens, the rubber base is removed, and the flask is placed inside a kiln to burn out the wax, leaving behind pathways for the molten metal to flow into the parts.

and the completed photo holders!

Here are the little photo holder guys after being cast in bronze, cut off the "tree," and polished up a little bit.
They were really fun to stack in interesting ways.
I drilled tiny holes and pressed in two little pins to hold each pair together. Since I had three pairs, I tried out some different finishing options. Here you can see one highly polished pair, one heated and treated with black patina, and one polished, patina-ed, re-polished, green patina-ed overnight, heat-treated, and black-patina-ed.
Here's a close-up of one of the bronze pins.
And the final product works! It makes a pretty good business card holder too.

silicone molding process

Here is the story of how I made multiple copies of my photo holders.

First I sketched how I wanted the photo holder to work. I was inspired by the idea of having it look like two little people were leaning against each other and holding the photo with their hands. Since the two little guys were identical halves, it was perfect for a multiples casting project.

I carved a hunk of wax using the bandsaw, jeweler's saw, Fordom (like a Dremel), X-acto knife, and smaller sharp carving blades. It was tricky to get the 3D geometry right (this is not the first piece of wax I attempted to carve this design in...).

Then I bent aluminum into a U shape large enough to contain the little guy, cut two side acrylic panels, and sprued my wax carving in the center (the pink wax above) to create a path for the wax to flow.
I filled the mold with silicone and got the bubbles out by letting it set up in a vacuum chamber.
Then I cut the mold basically in half, but actually the dissection was a little more complicated for this shape and it had about 4 main cuts. All this slicing ended up breaking the original wax guy, but that was fine because now with the mold I could inject lots and lots of little wax guys.
Here is the vacuum chamber, original blue wax carving, lots of attempted half-injected pink waxes, a couple of good ones, and the mold at the right.