Zinc electroplating

[Eugen]

I'm going to be plating some parts with zinc and thought I'd share the process with you guys. This is one of the easiest plating processes both in terms of procedure and ease of finding the necessary material. My source of information was an article written by Darlene Martin from Plating Resources Inc. I saved the article a while ago, and it's a good thing that I saved it because it appears to have disappeared from the internet, or at least I can't find it anymore.

The article covers multiple ways of doing zinc, nickel, and other metals, and a text version is attached here for your fun and delectation.

For me the easiest procedure was the alkaline formulation of the bath because it's the easiest to find the ingredients for the bath:
1. Distilled water (if you're a purist). I am guilty of using tap water once or twice.
2. 40 g/liter Sodium carbonate. This is a fancy name for washing soda. Here in Canada you can find Arm & Hammer "So Clean" washing soda at Canadian Tire for about $5 a box. You can also make your own from baking soda. Put baking soda in a pan and heat it up while stirring continuously until it no longer bubbles.
3. 90 g/liter Sodium hydroxide. This is caustic soda, or lye. I found caustic soda crystals at home hardware, about $30 for a 2 liter jug. I used it in making my own soap and still have some around.
4. 1/2% per volume Addition agent. My understanding is that the addition agent ensures a bright plating, which I don't really care about. The quantity is also very small anyway.

The formulation calls for zinc metal, 15 g/liter.

In the past I have used a battery charger as source of current, set on the 2A setting. I'll show some pics when I start plating stuff.

Anyway, join in the discussion if interested, it's not like I know this perfectly, but I have plated some parts successfully.

[Harry]

Interesting post Eugen! I’m all ears to hear about the process. My only knowledge about plating was from a few welding repair jobs I did at a plating company. They did plating of many different metals and the acids used to clean the base metals were very caustic. This place was a cesspool to work at.I just did a few repair jobs for them and they were very happy with my work. They wanted me to come back but I had to turn them down because I didn’t want to get exposed to the chemicals in the air. Harry

[RoamingGnome]

Interesting topic @Eugen Thanks for sharing...

[DavidBarkey]

Thats neat @Eugen . What is Addtion agent?

[Eugen]

Thats neat @Eugen . What is Addtion agent?

Exactly I don't know.
I used once a little tsp and other times nothing.

[Eugen]

Was going to do a little plating and can't find that lye. Where does the lye lie? I knew I had some left, but then again, maybe it's all gone.

So, plan B. Vinegar! That I got, plenty of. I try to always have a couple of gallons of that cheap vinegar around. And ammonia, but that's a different story.

There's another recipe like this: vinegar, water, and a fistful of salt. Vinegar, check. Water, check. Salt... just the pink joke from wherever in the world it comes from, 'cause I'm drat sure it's not from Himalaya. Let's experiment then, in a plastic container, add a gallon of vinegar, add a gallon of water, throw in a cup of washing soda (sodium carbonate). Let it finish bubbling, then two straps of zinc near each other in the bath, one on the positive one on the negative of the battery charger, on 2A limit. One of the zinc strips should show bubbling on its surface nearest the other strip. Let it go like that for about 40 minutes. The idea is that zinc will release into the bath ions, cat ions, or whatever they are called, my chemistry is not so good.

Fine, now here are the parts I want to plate. See how I did not wire bush clean all of them perfectly. Unfortunately I did not have enough patience for that last night. This reminds me to build that parts shaker that it's been on the todo list for a million years.

String them on a wire, put them in the bath on the negative wire. The zinc electrodes/strips go on the positive. And let them bubble.

Here they are after about 3 minutes.

Notice how some areas are already plated, but others, which have not been cleaned well, are darker and not plated (yet?). I put them in and will let them go on for about 20 minutes, see if it made any difference to the dark areas. Stay tuned.


SAFETY WARNING: don't drink the chemical bath, don't let it jump into your eyes, wear gloves, wear glasses, wear a jacket, do this in open air and don't sniff the gases, because I have no idea if the fumes are flammable or bad for your lungs. Better yet, don't do it because I don't know if it's dangerous. If you do it and you get hurt or you burn your house it's not my fault.

[RoamingGnome]

SAFETY WARNING: don't drink the chemical bath, don't let it jump into your eyes, wear gloves, wear glasses, wear a jacket, do this in open air and don't sniff the gases, because I have no idea if the fumes are flammable or bad for your lungs. Better yet, don't do it because I don't know if it's dangerous. If you do it and you get hurt or you burn your house it's not my fault.

"Don't drink the chemical bath..."

We need to find you one of those kids chemistry sets from the '50s and 60's... don't know how my generation survived

[Eugen]

@RoamingGnome


Ok, so the experiment continues. The parts that were not exactly cleaned well of rust went back in the plating bath for about 1.5 hours.

This is the result.

One not rubbed the other two with some rubbing for shine.

I declare the experiment a succes.

[DavidBarkey]

SAFETY WARNING: don't drink the chemical bath, don't let it jump into your eyes, wear gloves, wear glasses, wear a jacket, do this in open air and don't sniff the gases, because I have no idea if the fumes are flammable or bad for your lungs. Better yet, don't do it because I don't know if it's dangerous. If you do it and you get hurt or you burn your house it's not my fault.

"Don't drink the chemical bath..."

We need to find you one of those kids chemistry sets from the '50s and 60's... don't know how my generation survived

Natural selection . The dumb ones didn't make it .

[Eugen]

Comparison. Zinc plated and wire brushed vs the old state still to be done. The zinc layer is thick enough to take a good brush on.