Electroforming on Beads

In this article, I hope to present a very simple description of electroforming. In his book, Jewelry: Concepts and Technology (New York, NY: 1982, Doubleday), Oppi Untract defines electroforming as the “process of synthesizing a metal object by controlling the electrodeposition of metal passing through an electrolytic solution onto a metal or metalized form.” Very simply, a metal skin can be built up on a metal surface, or any surface that has been rendered electroconductive through the application of a paint that contains metal particles. This differs from electroplating basically because the skin is much thicker and can exist as a self-supporting structure if the original matrix is removed.

I will discuss electroforming on glass beads here, but the concept is the same whether the object being electroformed comprises glass, wax, or really anything that can stand up to the acid in the electrolytic solution. The object being electroformed can be a permanent part of the end product or can be temporary (as in the case of wax), and removed later, leaving only the metal form, the “electroform.”

The easiest (and safest) metal to electroform onto a surface is copper, which can be plated later in gold or electroformed in silver.

The basic concept involved in electroforming is relatively simple: the rectifier supplies both positive and negative current; positive to the anodes (the copper plates) and negative to the cathode (the bead painted with the electroconductive paint). The anodes (I use 2) and the cathode are suspended into the beaker containing the electroforming solution by 18-gauge copper wires, which are attached to 8-gauge copper rods placed over the Pyrex beaker. The positive and negative lead wires coming from the rectifier are clamped to the ends of the 8-gauge copper rods. During electorforming, copper molecules leave the anodes and go into the electroforming bath; copper molecules present in the bath deposit onto the cathode (your painted bead).

To prepare your bead to be electroformed, make sure it is well cleaned. Paint the electroconductive paint where you want the copper skin to grow.

The copper skin won’t permanently adhere to glass, so make sure that the paint is applied as a shape that won’t peel or slide off the bead. In other words, make sure it will be firmly anchored as a result of the shape it takes. Electroforming a ring around a spherical bead won’t work, nor will electroforming the tip of a cone shape. The resulting copper skin could come right off. Electroformed copper around two-thirds of a bicone will remain permanent as will a sheath that goes around an urn shape and through its handles.

Allow the electroconductive paint to dry for about 2 hours. I just stand the bead, stuck on a wooden toothpick, into a Styrofoam meat tray. Do not handle the painted portion of the bead – oil from your fingers may hinder the electrodeposition.

To prepare your anodes, drill a hole in one of the 1″ ends of your small rectangles of copper (this is where the 18-gauge wire will attach to suspend it into the bath). Make sure that the anodes are clean. You can use an abrasive pad to clean the surfaces.

Cut the 24″ of 8-gauge wire into 3/8″ pieces, which will be placed over the Pyrex beaker. Fill the beaker with electroforming solution to within about 2″ of the top.

Cut 2 pieces of 18-gauge copper wire that are long enough to suspend the 2 copper rectangles in the solution but short enough so that the drilled holes and suspending wire are not submerged. Wrap the other end of each 18-gauge wire around the middle of the outside rods of 8-gauge wire.

Your bead, the cathode, is suspended in the bath by another piece of 18-gauge wire. The wire should go through the hole in the bead, and be bent in such a way that it comes in contact with the paint on the bead.

Attach the other end of this wire to the center rod of 8-gauge wire hanging over the beaker. This wire is conducting the negative current to the bead, which will cause the electrodeposition of copper molecules. Be careful that the top hole of the bead, where the wire is entering, isn’t submerged into the bath. You don’t want the wire to have electrodeposition as it both enters and exits the bead, or it will be difficult to remove. The bead should be hanging in the center of the beaker, with an anode on either side of it. Try to space the anodes at an equal distance from the bead (the cathode).

You are now ready to turn on your rectifier and begin electroforming! Be sure that the 8-gauge wires over the beaker do not touch. Positive and negative contacts may blow out the fuse in the rectifier (if your model has one). Turn the knob to see if the needles indicating voltage and amperage move. If they do, you have set up a system that carries a current. If they do not, here are some items to check:
1). Your alligator clips at the ends of the lead wires (which are clipped to the 8-gauge wire rods over the beakers) – make sure they are clean and rust-free. If they look old and dirty, use a household file to clean them up.
2). Your 8-gauge wire rods – make sure they are free of copper salts. A quick cleaning with an abrasive pad will help here.
3). Your rectifier – make sure it is plugged in and turned on.

A slow deposition of copper using low voltage is preferable over a rapid buildup, which will frequently crumble off. I use under one volt of current (which you control with the knob on the rectifier) when I electroform, and the process can take around 18 hours or more for one bead depending on the thickness desired, the area covered, etc.

STEP 10.
During the electroforming process, change the point of contact between your bead and the wire conducting the charge to the painted surface several times. If you leave the wire in one spot during the entire procedure, that spot will not be covered with copper.

I wait until the copper skin has begun to grow consistently over the bead, and no paint is showing. I then remove the bead from the bath, carefully rinse and dry it, and paint electroconductive paint over the place where the wire had made contact.

When it is dry (about 2 hours), I reposition the wire to touch another spot that has already begun to electroform and return the bead to the solution.

STEP 11.
Periodically during the electroforming, it is a good idea to clean your anodes. When you remove them from the bath, you may notice that a residue has darkened the copper. You may also notice a buildup of copper salts. Both can be removed with an abrasive pad.

STEP 12.
When your bead is electroforming, you will find that the copper skin is rather baroque and can be granular, compared to the thinner coatings achieved through electroplating. In addition, you may see that the skin has built up unevenly over the surface. Because projections of any kind are places of high-current density, there will be more electrodeposition at peaks, ridges, and squared edges than there will be on round edges or flat surfaces. This can serve to define the shape of the bead and create textural interest.

STEP 13.
When you are satisfied that your bead is electroformed as heavily as you want it, remove it from the bath and rinse it. The color will be a matte pink. To bring out a bright copper shine, gently scrub the bead with a brass brush lubricated with liquid detergent. Electroformed copper oxidizes quickly when left in the air. You will need to seal the surface with lacquer to prevent this. You may prefer to patina the copper with one of the solutions available through jewelry supply houses.

Kate Fowle
The electroforming solution can be reused, as can the anodes. Make sure you filter the electroforming solution through two coffee filters dampened with distilled water before returning it to its original container.

The relatively simple process of electroforming can add real textural interest to your beads. Experiment and have fun with it! And please remember to read and familiarize yourself with all the warnings printed about the materials you will use – your health is your responsibility!

Kate Fowle is a glass bead artist and teacher based in Washington, DC. You can check out more of her beads at http://www.katefowle.com/.

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