Lava Ring by Angela Baduel-Crispin

This unisex ring has a slightly rough, masculine look and can be a great gift for a man. It has a firing temperature adapted to allow Art Clay™ copper to sinter while being fired together with fine silver, in a way that is safe for both metals. 

The advantage of using a commercial fine silver ring liner is that it guarantees strength and avoids direct skin contact with the copper when the ring is worn. Using a manufactured ring liner instead of making your own fine silver flared ring shank also saves you time.

A fired silver clay ring shank can be used, if you prefer, but it should be sturdy and fired for 2 hours at 900°C regardless of the brand of clay used.
It is important to fire only unequal amounts of copper and silver (i.e. unequal mass), because firing copper and silver of equal mass together tends to make them alloy (see “Caution” at the end of this article).

Co-firing silver and copper clays: In general, it is possible to fire copper and low fire silver clays together successfully as long as they are not in equal amounts (so they don’t alloy) and as long as the temperature is adjusted to suit both clays. For silver ring shanks, however, co-firing silver and copper clays is not recommended. The short (30 minute) firing time required for the copper clay, which helps to reduce oxide build-up, can compromise the strength of the silver clay band (which should be fired for a full 2 hours at 1650°F), while firing the copper clay for longer than 30 minutes produces a thicker layer of copper oxides on the surface, reducing the thickness and strength of the copper metal after the oxides are removed.

Project Materials and Supplies

Materials:

  • Metal Clay Findings 8mm flared ring liner
  • Art Clay™ Copper
  • Gloves in a Bottle® barrier hand cream
  • Isopropyl alcohol
  • Jewelry concrete or a sculpting concrete
  • and compatible colorant

Tools and Supplies:

  • Cotton swabs
  • Coarse sandpaper (280 grit)
  • Clay extruder with a 3.5mm round-hole shaping disc insert
  • Plain white paper (optional)
  • Ceramic tape/kiln shelf paper, such as Bullseye ThinFire paper (optional)
  • Watercolor paintbrush
  • Craft knife
  • Silicone-tipped clay shaper, size 0
  • Dust mask or particulate respirator (recommended)
  • Flexible sanding pad (fine grit)
  • Protective eyewear (kiln/torch glasses to protect your eyes from infrared)
  • Gloves
  • Long tongs (for reaching into the kiln)
  • Pickle solution
  • Burnisher
  • Bowl of water
  • Heat-resistant firing surface (for heat patina, optional)
  • Small disposable plastic container
  • Measuring spoon
  • Spatula
  • Soft cloth or sponge
  • Micron-graded non-woven polishing cloths (such as 3M™ Wetordry™
  • Polishing Papers – optional)
  • Wenol™ metal polishing cream
  • Winsor & Newton™ Wax Varnish or Nikolas Clear Lacquer spray (optional)

Note:

If your work surface, tools and/or supplies have been used with silver clay, be sure to clean them thoroughly before using them with copper clay (and then clean them thoroughly afterwards if you plan to use them with silver clay again). Alternatively, you can keep a duplicate set of frequently-used tools and supplies and dedicate them to copper clay use exclusively.

Equipment:

  • Toaster oven or other heat source for drying the clay (optional)
  • Kiln with kiln shelves
  • Rotary tool
  • Fine polishing wheel for rotary tool made with Scotch-Brite™, e.g., Galaxy™
  • polishing wheel (red)
  • Pickle pot
  • Torch (for heat patina, optional)

Safety

Safety notes:

  • Before working with copper clay, always apply a small pea-size amount of Gloves in a Bottle® protective hand cream to the front and back of your hands (to above your wrists), between your fingers, and under your fingernail Allow the cream to dry completely before you touch the clay.
  • Avoid touching your face or other parts of your body while working with copper clay.
  • Wear a dust mask or particulate respirator when sanding dry copper clay.
  • Wear appropriate protective gear, including kiln/torch safety glasses, heat-resistant gloves (and, ideally, a shop apron) when putting pieces into, or taking them out of, a hot kiln or when using a torch or other open flame. Have a heat-resistant surface nearby where you can place hot tools and metal.
  • Tie your hair back before working with an open flame or a rotary tool.
  • Wear closed shoes.

Project Step-By-Step

Step 1

Rough up the surface of the ring with 280 grit sandpaper, taking care to avoid scratching the side walls.

Step 2

Clean the surface with a cotton swab dipped in alcohol.

Step 3

Lightly oil the extruder and the shaping disc insert with the round hole. Place the disc insert in the extruder. Roll some copper clay into a compact ball, place it inside the extruder, and extrude a coil of copper clay.

Step 4

With a wet paintbrush, moisten the entire length of the clay coil.

Step 5

Cut one end of the coil at an angle, using a craft knife or clay blade. Place the angled end against the flared wall of the ring and lay the clay coil in a wavy pattern around the ring as desired.

Step 6

Overlap the remaining end of the coil and cut it (at the same angle as the first end), leaving a few millimeters of overlap. Blend the two ends together thoroughly with a clay shaper to make a sturdy joint.

Step 7

When the two ends are joined securely, reshape the coil as desired around the band. The clay has a tendency to spring back to its original position, so hold it in place for a few seconds.

Step 8

Continue shaping and holding the clay coil a little at a time until it maintains its wavy shape all the way around the band. Allow the clay to air dry or dry it with a heat source according to the manufacturer’s instructions. I used a toaster oven at 80°C/175°F for 10 minutes.

Note: The wavy shape of the coil means that it is longer than the circumference of the ring liner, thereby allowing the coil to shrink around the ring band without cracking or breaking. If you prefer to make a straight band of copper instead, wrap a few layers of paper around the recessed area of the silver band to accommodate shrinkage before adding the copper coil. Since the paper will burn very quickly, you also can add a strip of ceramic tape over the paper to prevent the copper from coming into direct contact with the silver during firing. This will make it easier to remove the copper oxides after firing since they will stick to the ceramic tape instead of to the silver ring liner. It also makes the copper coil into a “spinner” that will rotate freely around the recessed center of the silver band.

Step 9

Fill in any gaps by moistening the dry clay and then pushing fresh clay into the gaps and smoothing it with a clay shaper. Allow these repairs to dry. Then Use a clay shaper to rub off any excess clay on the silver band.

Step 10

Scrape any bumps off with a craft knife.

Step 11

Smooth and even out the surface with a fine grit sanding pad cut to size.

Note: In this photo of the sanded surface, the little black marks are stiffer bits of clay that had begun to oxidize in the re-hydrated clay that I used for this project. These slightly oxidized bits of clay did not have any negative effect on the end result.

Step 12

Preheat the kiln to 920°C/1688°F. Place the ring directly on the kiln shelf in the preheated kiln and fire for 30 minutes. This temperature allows the copper clay and fine silver to be fired together because it is still below fine silver’s melting point (960°C/1760°F) and close enough to the copper clay manufacturer’s suggested firing temperature for the copper clay to sinter.

Note: Before firing the ring, I recommend testing your kiln to make sure that it does not fire too hot.

While the ring is being fired, prepare a bowl of water and place it right in front of the kiln door (or right next to the kiln, if you have a top-loading kiln).

After the firing cycle is complete, allow the kiln to cool down to approximately 600°C/1100°F (it should no longer be red inside). While wearing protective gloves and eyewear, remove the ring from the hot kiln with long tongs and plunge it into the cold water. A lot of the copper oxides will flake off.

Step 13

If any oxides remain after you have quenched the ring, place it in a pickle solution. Leave the ring in the pickle for around 10-15 minutes, or as long as necessary for the copper to return to its pink color.

Step 14

Clean the entire surface of the ring, using an electric rotary tool with a fine Scotch-Brite™-covered polishing wheel (such as a Galaxy™ red polishing wheel). Some oxides may “hold” the copper coil to the silver temporarily, so thoroughly remove any oxides on the sides of the coil or under it.

If you made a spinner ring: Clean the surface completely and gradually loosen the copper coil from the silver until it can turn freely around the ring liner. Brush the exposed surface with the polishing wheel, as above. Reminder: If you cover the recessed area of the silver ring liner with both plain paper and a strip of ceramic tape before adding the copper clay coil, the ceramic tape will prevent contact between the silver and the copper as the clay shrinks, which will allow the spinner to turn immediately after it has been fired.

Step 15

Burnish the top and sides of the ring with a burnisher to unify the surface, close any pores and remove any scratches.

Step 16

To add a heat patina (optional), place the ring on a heat resistant surface. Using a soft reducing flame (less oxygen), move the flame slowly over the ring to heat it up, then sweep the flame across the copper, a little at a time, to change its color gradually.

Step 17

Place a small amount of concrete for jewelry in a disposable container. Mix it with water in the following proportions: 1 part water to 4 parts jewelry concrete (I use the same measuring spoon for both). Add a pinch of dry colorant and mix well. Allow the mixture to sit for 1 to 2 minutes.

If necessary, add more water in very small quantities to achieve the correct consistency.

If too much water is added, add more cement powder. You want the mixture to be the consistency of a thick, somewhat granular cream with a slightly wet surface.

Important: If more water is added, the working time will be reduced from approximately 30-40 minutes to approximately 10 minutes.

Step 18

Center the fired copper coil on the ring band and hold it in place. Use a spatula to apply the jewelry concrete, filling the areas on both sides of the copper coil. The coil has an undercut, which adds a mechanical bond as well. Smooth out the concrete with the spatula, pressing it down gently so it reaches all the way to the flared borders and under the coil.

Work your way around the ring, adding the concrete in sections and continuing to hold the copper coil in place.

Step 19

Use a soft cloth or a sponge to smooth out the surface and remove any excess from the copper and the sides of the ring. Allow the jewelry concrete to set. The cement will further set over a couple of days, after which it can be wet. Although the cement needs no particular protection, a wax varnish or another sealant can be applied to the ring in order to protect the copper patina.

Caution: Equal amounts of copper and silver fired together while touching each other, may result in a meltdown. The ring in the photo was made using COPPRclay™ and fired using a two-phase firing schedule (open-air firing followed by firing in coconut carbon).

About the Author

Angela is a globe trotting artist who was born in Brazil, went to school in Hawaii and now calls France her home. Her work has graced the pages of Metal Clay Artist Magazine since our first issue! Angela’s style and work evolves every few years, usually after a prolonged time of reflection and time with her family. Family is of equal importance to Angela as art. She is the proud mother of two beautiful and smart kids who are growing up too fast. But as smart as they are, Angela is still able to win all deputes as she is the only one in house to speak three languages!

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