by Thomas Jarvis
Revision 2 - 13 September 1999

1.  In a plastic container with a wide lid, prepare a mixture of distilled water, lye, and NaCl.  Use 4 grams per liter of lye and twice as much NaCl. To avoid any possibility of silica contamination from glass being in contact with lye water use HDPE plastic for the electrolysis and storage tanks. Also use plastic utensils.  The acidic solution can contact glass in the last couple of steps.

2. Cut two pieces of solid copper wire of a gauge between 10 and 18 to a known length. Weigh the wire and determine the weight/length ratio (15 inches of 14 gauge wire should weight approximately 7 grams).

3. Place one wire 1.5 to 2 inches into the solution. This will be the cathode (-). Place the other wire 0.5 inches into the solution. This will be the anode (+).

4. Hook up the source. This process has been done with both ac and dc sources and a range of voltages and currents. They all work. For a dc source, advance the anode a little twice each day, and swap polarities on the electrodes every one or two days. Avoid getting a long length of anode into the solution because this can result in necking and breaking off of the tip of the wire. For an ac source, there is no need to swap the electrodes. Keep one electrode 1.5 to 2 inches into the solution, and the other about 0.5 inches in.

5. A black powder will settle on the bottom of the tank. Once 1.33 grams per liter of copper wire has been dispersed, stop the electrolysis. 0.5 grams per day of copper dispersed is a good rate. If your rate is less, you may need to increase the voltage and/or current.

6. Siphon / decant the clear liquid above the black powder and put it in storage. It will look like plain water, but is caustic. Mark it accordingly.

7. Dissolve the black powder and small amount of remaining liquid into a 15% HCl solution. The total volume of acid solution should be approximately 1/6 the total volume stored in step 6. The result should be a transparent green solution. Store this for at least two days in a warm, dark place.

Without the heat and/or the storage time, the white precipitate will not form.  Upon adding the lye water, the solution will transition from green to blue.  The blue will then congeal and condense back into the black powder.

8. Transfer the green solution to a container suitable for heating. Heat to 70-80 degrees C. Do the same with approximately twice the volume of the stored lye solution.9.  Slowly add the hot lye water to the hot green solution.  It is not necessary to do it drop by drop, but a fast rate would be dangerous.  A $15 plastic coffee maker dedicated to this purpose is ideal.  Put the green solution in the pot and get it hot.  Pour a portion of cold lye solution into the hopper and let it drip through. The pH is highly unstable during this process.  It will shoot up high when a new addition of lye water is made, then gradually stabilize.

10. A white precipitate may form where the lye water drips into the solution. If the solution is still green, this precipitate will re-dissolve. Allow it to re-dissolve before adding more lye water. When the solution transitions from green to blue, stop adding lye. The white precipitate is stable in the blue solution.

"Stop adding lye" refers to the addition of the heated lye water to the colored solution. The pH at the blue-green transition point measures between 9 and 9.5 on my pH paper in the last steps.  I've added a little lye solution then a little acid solution and had it go back and forth: green to blue and back.  This transition point is different from earlier in the process.  When dissolving the black powder gradually, the solution will remain blue until it is quite acidic.