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Zinc Electroplating for Car Restoration

I own a small automotive shop and more and more, we are performing restoration work on older cars and hot rods. The biggest problem currently is finishing old hardware. Bead blasting and painting bolts, nuts, linkages and brackets is only good for short term appearance. I have read many posts and still lack the basic skills to zinc electroplate common items.

As pathetic as it sounds, I wish to use the simplest and cheapest method possible, for many reasons. But, I am doing something very WRONG. I have used vinegar, epsom salt, and sugar as my electrolyte. Applied 1.5, 3, 4.5 and 6 volts at 300 milliamps. Cathode neg and Anode pos. DC. For a cheap and easy source of zinc, I have stripped some common carbon/zinc batteries stored for recycling. The only thing I make is bubbles. Maybe you could help me out on a few details. If I use 1 gallon of vinegar [in bulk on eBay or Amazon], how much epsom salt and sugar should I use. In units of measure, not weight. I know this must sound absurd to you, but I have no way of measuring by weight in grams. Should I increase my amperage? How long should it take to plate? Is too much bubbling an indication of something going wrong? Should I leave the zinc strips sit in the electrolyte all of the time?

If I need to switch to other ingredients, like boric acid or potassium zinc chromate, where do I get these? I would bet that these are common items, but marketed under different names for different everyday use in certain products, but what ones? (if any, I understand that this is just an assumption)

Thanks for everyones help,
Give me a fish and I'll eat for a day, teach me to fish and I'll eat for a lifetime.
I think this applies for me on this topic very well.

Brett M
Car Restoration - Angola, Indiana, USA
November 5, 2010

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November 8, 2010

Hi, Brett

I don't want to assume what you know and don't know, and lead you into trouble. So, instead, let me take it from the top:
Most plating is done by plating shops. Have you considered looking into having a plating shop do this for you?
Electroplating was our nation's very first EPA categorically regulated industry. You need to think twice before selling plated parts or plating services and becoming a regulated business.
The "plating formula" you are using was invented by my friend Tom Pullizzi as a safe demonstration of plating for elementary school children. It is intended to show children a scientific principal: the plating has virtually no thickness, and no functional value at all. Building upon this for a functional plating solution is a bit like taking a clay automobile model out of a wind tunnel and trying to tune it up to win a drag race with it. The vinegar plating solution and the clay model are only for demonstrating limited principles, and you can't build upon them.
Chromates are the toxic stuff of Erin Brockovich exposes, and are not in any household products.
If you want to try a slightly more realistic plating process, you can get a small tin-zinc plating kit from Eastwood for about $75. But real commercial electroplating is a venture that is hard to get into without spending real money, very big money. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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There are other companies that sell "plating kits" that are moderately functional for ones and twos but require lab testing for even limited production.
The first problem is getting rid of the chemicals as they are exhausted. For this, you need DOT registration to even carry it next door.
The real problem comes when an irate customer or ex employee turns you in. This results in fines starting at $500 each per day.

Find a good small shop. You will be glad that you did.

James Watts
- Navarre, Florida
November 9, 2010