Hydraulic Die Press

This month, we asked Lisa Krikawa of Tucson: If you were stranded on an island (that just happened to have a bench in the middle and some metal hanging around), what tool would you want to have that allows you to do things you can't do with any other tool?

So tell us. What's your secret weapon?

Hydraulic die press.

Why do you love it so much?

It's just so mechanical — a simple but powerful tool. It's basically a plate that enables you to push sheet metal with force into any cavity to create a three-dimensional form. You can also achieve different textures by pressing precious metal onto other metal forms, such as heavy mesh or perforated metal. I love how the metal responds like fabric, sliding effortlessly into place. There's nothing fancy about it — except the complex textures and shapes that it allows you to achieve for jewelry.

How do you use it in your work?

I use the hydraulic die press to create simple to complex three-dimensional designs from sheet metal, predominantly pendants, earrings, and lockets. One of my favorite pieces is something we call the "lifesaver" pendant (top right). It's a beautiful torus shape. To make the die for the piece, I lathed out the cavity for half of the donut shape, which is about 1.25 inches across, in an aluminum block. The metal is pressed down into the cavity by the male die and stretches out evenly.

What does it enable you to do that no other tool does?

With this tool, you can give a piece of sheet metal so much body and still retain its light weight. You can create unusual designs and keep the price point down because you are using a very thin piece of metal. (I prefer 24 gauge.) Many of the designs I make with the press could never be made solid because they would be too heavy — and much too expensive.

Due to the economy and the price of precious metals, one of the current trends in jewelry is for volume without a lot of weight. The press can help you to achieve lightweight forms for a production line that could not be created through casting.

As long as the outline is symmetrical, you can press two pieces into the same die and then solder them together, and they will fit perfectly. While the "lifesaver" pendant is a simple example of this, you can use the same process to make more complex, detailed shapes. I've shaped a screw this way so that when the two pieces are attached it resembles a unicorn's horn. I also love using the press to make lockets.

What discoveries or breakthroughs have you made with this tool?

I've learned a lot about making dies using the hydraulic press. To create the female die into which the metal is pressed, I usually either carve it out of aluminum or make it out of liquid steel. I also cut shapes out of heavy-gauge aluminum sheet and Plexi Glass — more common techniques.

Although neoprene is frequently used as the "male" die, plastic and metal male dies can also work well, particularly for deep or detailed forms. I prefer metal and plastic male dies, as a solid form helps the metal move down into the cavity, preserving the thickness of the sheet. Conversely, when you use neoprene for the male die, you actually pinch the metal to the flat die face and force the remaining metal to be stretched into the die, making it much thinner.

By using very thin sheet metal, you can achieve even more complex patterns. I can get such a detailed piece out of a carved aluminum block using 26 gauge metal — there are so many curves and ins and outs that the design of the piece becomes very strong. It's hard to believe that it started out as a piece of sheet metal.

After I started using the press, I'd look around and realize how many products are manufactured with this technique. Once again, the jewelry industry is not reinventing the wheel; we are borrowing technology from other industries and applying it to precious metals on a small scale. I love it!