How to Cast Metal Toggle Clasps

Design and cast your own precious metal toggle clasps to use on handmade necklaces and bracelets.

Handmade, cast metal toggle clasps add style to the necklaces and bracelets they connect, and blend in seamlessly when custom cast in a matching design. Toggle clasps consist of two elements: a circle or similar shape with an open center and a straight bar, thin enough to fit through the circle, yet long enough to stay in place once inserted. Although toggle clasps are not as secure as lobster clasps, they are easier to use and enhance the overall appearance of a piece of jewelry.

Things You'll Need

• Metal pot
• Jeweler's wax
• X-Acto knife
• Clay modeling tools
• Wax pen
• Wax rod
• Casting flask
• Investment plaster, 4 cups
• Room-temperature water, 4 cups
• Electric kiln
• Metal tongs
• Centrifugal casting machine
• Casting metal
• Crucible
• Ring vise
• Jewelry saw
• Metal file
• Hard-bristled toothbrush
• Buffing wheel

Instructions

1. Heat a pot of water to boiling, then turn off heat. Dip the sheet of jeweler's wax into the water to soften, then cut out the basic shape of the two sides of the toggle clasp using an X-Acto knife. Carve and mold the shapes into the desired designs using the clay modeling tools.

2. Plug in the wax pen, an electric heating iron similar to a soldering iron, then turn it on. Cut two lengths of wax rod 2 inches long to serve as the sprues, or wax mounts, for the two toggle elements.

3. Touch the wax pen to the end of one sprue, then hold it against the side of the circular element to attach. Touch the wax pen to the end of the other sprue then hold it perpendicular to, and at the center of the bar element to attach. Touch the wax pen to the other end of the sprue attached to the bar, then hold it against the opposite side of the circular element to join them all together in one line.

4. Remove the cylindrical metal walls of the casting flask. Place the rubber flask base flat on a table. Mount the free end of the sprue attached to the circular element into the hole at the center. Attach the flask walls carefully back onto the base.

5. Mix the investment, a fine plaster used for detailed casting, with the room-temperature water into a creamy consistency. Stir thoroughly to eliminate air bubbles. Tilt the casting flask slightly and pour the investment mixture into the cylinder. Place the flask flat once full, then tap the sides for 5 minutes to release additional air bubbles. Allow to dry for 24 hours.

6. Flip the flask over and remove the rubber base. Place inside the kiln and heat to 1,200 degrees Fahrenheit. Bake for one hour to burn out the wax inside the mold. Decrease the heat and remove the flask using tongs once cooled to 400 degrees.

7. Place the flask inside the centrifugal casting machine, sprue-hole side up. Heat the casting metal in the crucible until molten. Turn on the casting machine and slowly pour the metal into the sprue-hole. Turn off the machine once all the metal is inside the mold. Allow to cool for 15 minutes.

8. Lift the cooled flask out of the casting machine with tongs and drop into a pot of cold water to quench. Shake the mold to dissolve the plaster then remove the cast toggle clasp from the water.

9. Secure the cast metal in a ring vise. Saw the sprues off with the jewelry saw. File down bumps with the metal file, then scrub off dried investment plaster with the hard-bristled toothbrush. Polish the two sides of the toggle clasp on the buffing wheel to complete.

Tips & Warnings

• Use caution and follow the accompanying instructions when using the wax pen, the kiln, the centrifugal casting machine and the crucible to avoid injury.

• Melt metal in a well-ventilated area to reduce exposure to toxic fumes.

References

• "The Complete Metalsmith"; Tim McCreight; 1991
• "Professional Jeweler Magazine"; Article Archives; Cast jewelry: A Primer; Mark B. Mann, May 1999