Homemade nickel plating with coins

[celsoari]

In this video I used pure nickel coins to finish some mechanical parts.

Greetings from Brazil

Celso Ari

 

[graham-xrf]

I also use an acetate bath to nickel plate. To produce enough plating passivation sufficient to stop iron content parts from rusting only needs fractions of microns. The plating thickness is too small (for me) to measure. Usually, about 10 minutes to 15 minutes at a current between 0.5A and 1.0A is enough.

If the part is to be used, and faces some wear, then leave it in for about 45 minutes.

I have found that as the solution is used, it gets darker green, up to a point where it goes stable. Several YouTube contributors recommend some salt in the solution to increase conductivity, and this works, I have found that if the solution is left for some weeks between times of usage, it goes a dark brown colour, but still plates nickel. This is not a problem, because the nickel has to be in there, and the anode can only pass more nickel into the solution. I simply added some diluted battery acid (H2SO4) a little at a time, while stirring, and the solution went back to bright green.

My starting point was about 3 or 4 years ago, from Geoffrey Croker's very basic video on how to easily get plating. I have had some strange results, including one where the (beautiful) plating came out contaminated slightly to make a slightly gold (ish) tinted colour.

I did learn that one has to use the pure spirit vinegar. Various "pickling" vinegar products look OK, but contain sugars, and other flavourings. You have to read the label carefully. Do not use brown vinegar. It maked a horrid dark sticky mess. Clean spirit vinegar works every time
I am not sure what happens if there is iron in the anode, but it does not seem to end up on the part being plated.

12 volts, from a supply capable of many amps is not a good idea. Certainly, do not use a battery. Any small ex-phone charger, or similar little supply can do. They may be only rated 5V, or 3.3V, or 4.7V, whatever, but will current limit at less than 1A. It kind of overloads the little charger, and the voltage will end up at something quite low. I used a current controlled bench supply, and I discovered that a good conductive solution, running between 600mA and 1A, usually has about 3V to 4V across the electrodes. None of this is very critical. It just works easily.

Thanks for posting your plating work. You were plating onto zinc, which was itself previously plated onto the bolt.

 

[woodchucker]

I wonder if you can find STOP BATH for photography, it's Acetic acid, and no sugars or anything.

 

[homebrewed]

I wonder if you can find STOP BATH for photography, it's Acetic acid, and no sugars or anything.

Distilled white vinegar can be found at about any grocery store and in many hardware stores (it's used for cleaning). Much easier to get than stop bath, unless you already have some. These days you probably would have to order the stop bath concentrate. Some brands have an indicator dye so you can tell if the stop bath is exhausted, don't know if that would interfere with the plating process or not.

I've used both nickel chloride and nickel sulfate for plating nickel. We used it to protect gold-plated IC lead frames when cross sectioning them. Also selectively-plated PCBs. We did that to monitor the plating thickness. The gold was so soft that if unprotected it would smear (despite being potted up), making it impossible to accurately determine the gold thickness, We found that the plating quality improved if the solution was warmed and stirred while plating. A hot plate + magnetic stirrer worked well for that. The shelf life of the electroplating solution was almost unlimited, unlike the electroless nickel stuff.

 

[rwm]

Some say you need to plate with Cu first then Ni for optimal results. What do you guys say?

 

[homebrewed]

It depends on the application. Nickel plate doesn't adhere well to some things without an intermediate copper layer. Probably tempco mismatch but it might just be an adhesion issue.

 

[vtcnc]

Some say you need to plate with Cu first then Ni for optimal results. What do you guys say?

My understanding is that you need the copper substrate if you wanted a nickel finish on non-ferrous materials such as zinc or aluminum. Otherwise, you have adhesion issues.

Where I used to work, we nickel plated many, many tons of cast iron and mild steel with no substrate to great success - plating thickness target was about 5 tenths. They had been doing that for decades and continue to do so today.

Here is an interesting response to your same question over at finishing.com...

Nickel plating over copper flash

Nickel plating over copper flash

www.finishing.com