Power Supply for Hobbyist Zinc Plating

A. It would take dozens of D batteries in parallel to deliver 10 amps @ 1.5 volts. The parts cost for a line-powered 1.5VDC @ 10A power supply shouldn't be too much, perhaps an experienced electronics person could build one for you if you can't yourself. Try a surplus electronics store to keep the cost down. If 6 volts is really too much, then this might be the way to go.

A. Battery chargers generally supply unregulated, unfiltered power, with lots of ripple. This is good for charging batteries but not so good for certain kinds of plating. It's not hard to build a power supply. Radio Shack has a great little book with detailed plans for constructing voltage regulated power supplies. That might be the way to go, if you can't find a used one. By the way, controlling voltage and current with resistance can be done, but in the 5 - 10 amp range the resistance elements will have to dissipate a lot of power and can get mighty HOT.

A. Why don't you use the battery for the source of current in plating, and recharge a second battery with the battery charger [on eBay or Amazon] offline?

A. You could try using a PC switch mode power supply. These power supplies are usually thrown away with old computers, I'd be surprised if you had to pay money form one. The +5V output is regulated and usually have > 15A current rating. Make sure you use *all* the red and black wires at these current levels and keep below %80 rated output. These supplies are built at absolute minimum cost so don't expect them to be a rugged and reliable power source.

Happy plating
Adam

? What kind of plating you want to do? Decorative, Corrosion protection etc. What kind of solution you are using? How much money to invest?

A. Hi Joe. We don't comment on particular brands or sources (why?), but 16 V is far more than enough for zinc plating ... but iffy for anodizing some alloys. But there is a lot more to plating & anodizing than a power supply, so I would suggest trying some samples with whatever smaller equipment you have or can easily afford. I think you'll find bolts more difficult than you expect, so why not try to plate one with dry cells or an old 6-volt old tractor battery or battery for a child's ride-on toy before gearing up for production? Good luck.

Regards,

A. Hi Joe. My understanding is that switching power supplies involve using electronics to change the frequency of the incoming current from 60 Hertz to a much higher frequency so that the transformer can be much smaller; and that they became popular as a result of the micro computer revolution in the mid to late '70s because hobbyists and consumers didn't want to lug around a fifty pound transformer with their Apple 1 and such. Industrial plating, with its very high amperage power supplies (often many thousand Amps), was slow to adopt switching power supplies but they are no longer uncommon.

10 Amps is a very small plating power supply by industrial plating standards, but adequate for 30 to 60 sq. inch parts ... and for zinc plating and anodizing I don't think there's any particular advantage to a 10 Amp linear power supply over a switching one.

But the idea of keeping it simple and just flipping a switch and plating probably has a number of well seasoned electroplaters with their decades of experience chuckling ... which is why I'm suggesting you try to successfully plate one part before committing to refurbishing the plating on your whole tractor. Knowledge & experience, not a particular power supply, really is the heart of the matter.

Regards,

Hi Joe
As one of Ted's old platers ........
A couple of things you need to know.
Prep for plating is vastly more important than for painting. Do you have the the essential chemicals for this and how to confirm that the cleaning was successful?
And do you have the chemicals to remove unsuccessful plating? You are not going to get it right first time.
Assuming you get a good deposit, you need to know that nuts and bolts are particularly difficult. Inside threads are difficult to get coverage and male threads build up on the peaks and starve the valleys. So threads that fitted perfectly before plating don't any more.
I like to see people trying new ideas; But I also like old tractors! There surely must be a local plating company that would give you the finish you want at a fraction of the cost of setting up yourself.

A. Hi again, Joe. You can read and watch videos about how to rebound a basketball a hundred times, but you'll still totally stink the first time you hit the court. Please practice on scrap parts because, speaking of expensive, if you've redone the parts one-too-many-times and over-pickled them you won't be able to save them. If any of the parts are high strength steel, don't forget the baking before and after plating. Best of luck.

Regards,

A. Hi again. Please google for "bolt strength head markings" or a term like that. For someone to try to safely guess the strength and hardness of a fastener from a verbal description of a marking won't work.

Some fasteners are so hard that the specs forbid plating, but the basic idea of hydrogen embrittlement relief is bake before plating, then use only anodic cleaning and the mildest possible (or no) acids (substituting blasting for the oxide removal), then highly efficient plating (generates the least possible hydrogen), then baking again *ASAP*. Baking temperature 375 °F ± 25 °F for 3 hours minimum, probably up to 8 hours, and never use your kitchen oven for anything but food.

Keep in mind as you roam the internet for advice that "instructional" and "how to" sites are funded by advertising dollars, and their purpose is to earn advertising money from clicks. Many of the articles are written by people with zero experience in the subject; their expertise is limited to locating good 'key words' to draw traffic, then posting something they found that has those keywords :-)

So, just because they tell you how to do something and what supplies to buy is no indication that the author has actually ever done it or even been anywhere near the issue s/he is writing about :-( Although this site is also funded by advertising, we are fortunate to be blessed with many knowledgable readers, and we concentrate on one very narrow industry that the administrator has worked in for 50 years,

Regards,

A. Hi Rodney. You had posted your inquiry on a thread about student science projects, but I thought it better to move it to this page.

Last question first: You should not do copper plating under zinc plating; that will increase the corrosion rate of both the zinc plating and the underlying steel.

Please see our "Introduction to Faraday's Law" which explains the science behind the amperage and voltage needed for plating. You will need a capacity of about 10-20 amperes per square foot of surface area you are plating. The required voltage is about proportional to the distance from anode to cathode, but that anode-to-cathode distance tends to grow as your parts get bigger just based on practical issues of not wanting the parts to short circuit on the anodes. Parts in a beaker are generally close enough that 2-3 Volts will do but large parts will tend to be far enough away that about 6 volts might be required.

Luck & Regards,