Asselin.Engineer

Electroplating Nickel

2018/09/15
ece craft

Electroplating Nickel onto Copper

Copper corrodes faster at elevated temperatures and this scares me. Ideally, we would nickel plate our eskate copper busbars. Commercial solutions with nickel powders and acid kits are available. Unfortunately, they cost way too much for personal use.

Luckily, there are some crazy people online who are interested in nickel plating at home. We tried DIY nickel plating.

Preparing the solution

Get pure nickel. I bought small nickel pieces from ebay and regret it. You want long and thick electrodes to easily position them in a glass container. Nickel welding rods are good.

The recipe for the nickel plating solution is simple: put two pure nickel electrodes in vinegar and plug a 12V power supply in there.

I used 12V 3A on the second try and the measured current was around 0.3A. 12V is much faster than 5V when preparing the solution.

The solution (nickel acetate?) eventually turns light green. A day later it becomes almost turquoise. To get this deep green-blue color, we went through two small nickel squares. It forms chlorine gas? (don't breathe) and the nickel seems to slowly melt in the solution... All chemical explanations available in this technical document.

Plating Copper

After you get the turquoise color, get a smaller voltage power supply (1-5V) and replace the cathode electrode with your copper strip. If you invert the electrodes, no worries, you'll get a copper plated nickel strip! I used 5V 0.8A. The voltage is important because it determines if the nickel will plate bright or not. At first I had unsatisfying results when using 12V to plate. I find this counterintuitive. There are equations to determine the optimal power supply values but there are too many unknowns with our home made experimental setup.

Plug in the power supply and for every 1 minute interval, rotate the copper electrode. Ideally we would get two electrodes in parallel and put the copper in the middle. I will design and 3D print a tool for this one day.

Unfortunately I lost the best pictures of the final results. We were able to get a semi-shine nickel plating with this method.

Conclusion

The result are decent and the experiment technically works but this could be done much better.

We should use a mixing magnet and electrode supports. Variable psu for better current control, etc. Also, more tests would be required to determine the optimal plating time and shine factor. I did not check any specs on the copper before plating vs after plating. It will have to be done.

In the context of electroplating nickel onto copper for our electric skateboard battery pack busbars, we decided to abandon the nickel plating sidequest for two main reasons:

1) Copper heatsinks in computers and they seem to be fine. A computer case is not our environment but I believe nickel plating is overengineering and is not worth it.

2) It would take at least 2 days to plate all of the copper we have.

More Info

Good tutorial on instructables.

Easy home made video of the process:

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Quality plating: