Copper Display Electroplating With Cobalt Salts and Graphite Electrodes.

Introduction: Copper Display Electroplating With Cobalt Salts and Graphite Electrodes.

About: I am a part time hobbyists biotechnolgist with photonics background. I also have a YouTube channel too.


I discovered by accident that adding 20 g of cobalt chloride to 2 L of tap water and adding 100 ml of pure acetone then adding copper plate 4 inches by 6-inch 0.016-inch thickness plate can create green to copper orange colors.

Graphite rods (electrodes) for Negative are needed and the Positive is the copper plate.

Here is some info from Electrochemistry.

I am explaining some simple theories of how copper chloride is formed.

Anode (oxidation): 2 H2O(l) → O2(g) + 4 H+(aq) + 4 e−Cathode (reduction): 2 H2O(g) + 2 e− → H2(g) + 2 OH−(aq) Overall reaction: 2 H2O(l) → 2 H2(g) + O2(g).

From Electrolysis of water part.

The cathode is + and Anode is -.

So even if HCl is made by reacting cobalt chloride with water the cathode generates OH ions since most of it is a weak acid and OH ions also react with free cobalt ions to form cobalt hydroxide which is very insoluble in water and falls out of solution.



Tap water. 2 L

Cobalt chloride 6 hydrate. 20 g.

100 percent pure Acetone. 100 ml.


Copperplate sheet 4 by 6 inches.0.016 inches thick Hard copper.

Optional: Magnetic stirrer and Hotplate.

Wooden block 4 inches by 4 inches 4 inches thick.

Urethane Paint Laquer makes sure it has Petroleum products so it coats well.

2-3 L beaker or 2 L Microwavable Pyrex beaker.

Powersupply 0-15 volts, 0-2 amps.

Blue Acetic acid Silicone curing agent gel. Any type will do.

Bottles 750 ml times 2 to keep waste.

Step 1: Preparing Your Cobalt Chloride Solution and Electroplating the Copper Sheet.

Weigh out 20 g of cobalt chloride into a weighing boat and tar the scale first. Place it into the beaker and add 2 L of water to the Pyrex beaker. Add 2 L of water tap carefully and measure out 100 ml of acetone in a beaker. Carefully with stirring manually stir the cobalt chloride and acetone solution.

Set the voltage of your power supply to 13 volts 1 amp in an hr or so it should drop the current to 0.2 Amps.

Add some clamps and stirring is Optional. Place the clamps with the rod and have the copper sheet placing downwards Have the sheet of copper inserted 1/4 into the 2 L solution. This depends on the type of beaker or microwavable type beaker you have. 10 cm from the bottom of the flask Usually.

Hang the graphite (two rods) with copper wire and lower it only a few inches into the solution for the first Run. Copper is Positive and graphite is Negative.

Within 1-2 hrs let the plates dry on both sides for at least 12 hrs preferably 24 hrs before using the Urethane coating. method.

Lowering the graphite rod with clamps completely without the copper touching the solution will cause the plate to be completely green in 1 hr.

Step 2: Coating the Metal Partly After Drying With Urethane Clear Laquer.

Using a ceramic bowl etc, place the metal with electroplated coat into the bowl and add carefully wth a tablespoon (Metal) the Urethane Paint onto the Electroplated coat. Let it drip on carefully and do not brush it with anything allow the spoon with the Urethane to fully coat half of the metal.

Dry for at least 12 hrs, then flip the metal on the other side and repeat with the coating.

Once completely dry you can use wooden blocks to cure a coating on the metal to make it into a neat display. Curing takes 12-24 hrs and it is a bit fragile and requires temps around 25-30 degrees C higher temps may take longer.

Step 3: Conclusions

Well besides dealing with small amounts of copper chloride, cobalt chloride, and acetone waste this is a good method of coating copper sheets --- a copper layer with HCl that produces OH on the Positive and H on the negative which corrodes the copper a bit allowing HCl from the CoCl2 6H20 in water to make a fine coat of copper chloride.

Bottles of 750 to 1 L (2 of them or more to store waste) must be done too since this is toxic corrosive waste as well. Even tho this is complex thanks for reading this.


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    2 months ago

    I forgot to mention the OH produce a lot of cobalt (II) hydroxide and some of it attacks the metal and the residue of HCl slowly forms copper (II) chloride hydrate.