Need to start a Zinc Plating Plant

A. Short answer, you need to do some research on your own first, then you probably need a consultant.

A. Hi, Arvind.

You must start with a knowledge of what type of parts you will be plating so that you can determine a pretreatment sequence (cleaning, activation, and possibly initial plating layers like zincate, alkaline copper, or Wood's nickel, based on the material of the substrate). Then the plating sequence (acid vs. cyanide vs. alkaline zinc plating, for example). Then you select the required post treatment (probably a RoHS-compliant chromate, perhaps followed by a sealer topcoat, or a wax or a water soluble oil).

Next you consider such factors as whether you should barrel plate the articles or rack plate them, and whether the line will be manually operated or automatic. With this information and the production rate, you can begin sizing the process tanks and ancillary equipment. I have seen small production plating lines put together for $50,000, but I was also involved in designing one plating line where the concrete foundation alone cost a million dollars before we began setting the first tank. That line cost many millions of dollars.

You may possibly find a process supplier and/or equipment supplier who will help you through the entire design, but many years (or decades) of experience are required to make the right early decisions. So, as James says, you should probably retain a plating consultant before attempting to go too much further.

The best way to determine cost per piece (or kg, although that's a bad measure) is to request quotes from a couple of local plating shops. Best of luck.

Regards,

A. Hi Jigar. Try to search for a supplier of plating processes in Gujarat and ask them to send a technical sales representative to see you. Armed with their brochures and an hour or two of his/her time, I think you'll have a very general idea of what is involved, so that you can continue to study on your own for a while. You'll see recommended plating books on our "must-have books" page.

After you have the general idea, plus have leafed through three or four plating books, and read at least a few chapters from one of them, you'll be able to talk to a consultant and do initial planning on the installation. Good luck.

Regards,

Q. Thanks for giving me advice.
I have base knowledge about plating in two types (tank, barrels).
I need study full process of plating including chemicals used after process.

A. Hi again, Jiger. We may be having a little bit of language difficulty, but I don't quite understand what you are asking. If you are asking for the general sequence of operation, it is usually soak clean, electroclean, acid activate, zinc plate, chromate conversion coat, seal (necessary with some trivalent chromate processes) -- with rinsing between each step. Often there will be two colors of chromate rather than just one, and often a dilute nitric acid bright dip may be used between the plating and the chromate.

But there are entire 500-page books just on zinc plating, 500-page books just on the installation & maintenance of plating equipment, and 500-page books just on troubleshooting plating problems. So, in between my one-paragraph introduction to the plating sequence, and the thousands of pages describing the "full process" in plating books, do you have some specific questions we can try to help you with? Thanks.

Good luck.

Regards,

A. Hi Gosai. We appended your inquiry to a thread which should give you a good start. Best of luck, and get back to us with specific questions.

Hi Uzohu. A proprietary alkaline non-cyanide bath is most likely to meet your needs, unless you need full brightness, which may be better met with an acid zinc plating bath. That is a very big plating line, and if I were you I would not make any commitments or spend a dollar on anything except books before retaining a plating consultant. Good luck.

Regards,

A. Hi Mickey. You have to start the calculation by determining the surface area of the parts, but my gut feel is that the rectifier sizing sounds all right.

Now, you know that the experts' most important piece of advise is to hire a plating consultant, and their second piece of advise is to take the time to read a zinc plating book or at least the zinc plating chapter in two or three books. And we know that, in your early rush of enthusiasm and the business rush to strike while the iron is hot, you're probably going to blow off that advise :-)

So, moving on ... what is the sequence of operation you foresee (cleaning, activating, [plating], post-treatment)? I don't think the brass should go through either the same cleaning tanks or the same activating tanks as the steel. What about the rectifier for the electrocleaner? Best of luck!

Regards,

A. Hi cousin Matteo. That is a very low capacity operation. Most mid-sized barrel plating lines for parts of that sort produce about 10X as much weight per day. Thus, you might give serious thought to whether you would be better off farming your work out to a jobshop.

But if you're sure you want to proceed, my preferred steps would probably be --

- Contact two or more suppliers of plating chemistry (You probably know this, but plating shops generally don't make plating baths from raw chemicals; rather, they are supplied with the processes by knowledgable plating process specialists).
- Select the supplier you have the most confidence in, and have them plate samples of each type of part in their lab to ensure that they have a workable process. Make sure that they use the handling approach that you plan on using (probably barrel plating).
- Have them tell you the process sequence and the required immersion times and operating temperatures, and ask them to advise on the general needs for auxiliary equipment for each bath (does it need heat, cooling, air agitation, exhaust ventilation, filtration, etc.)
- Armed with this info, you meet with the used equipment seller and decide whether between the 3 of you -- process supplier, equipment supplier, yourself -- you have enough experience to handle all aspects of the design. If not, you hire a plating consultant before you buy anything or commit to anything.

Remember that the process will not run by itself trouble-free, so you will need some sort of laboratory capability to keep things on track. Best of luck.

Regards,

A. Hi Matteo, "small" is relative of course, but let me approach it this way --

In the USA there are very few "captive" plating shops anymore. Except in high tech fields, the work is always farmed out to plating jobshops. Zinc plating of hinges is exactly such "commodity" type plating that is usually farmed out. An average commodity zinc plating jobshop in the USA probably has perhaps 3 plating lines, although some shops might be 5 times that big. Each barrel plating line in such shops probably produces something like 3000 kg of zinc plated work per day.

Plating in Peru is doubtless different than plating in the USA, Mexico, China, or India, and there is nothing wrong at all with a small plating line. The general thrust of my comments though should alert you to the question of whether you can afford the lab services, the waste water treatment operation, a knowledgable maintenance department, chemical specialists, etc., when you have to pro-rate all that stuff across only 350 kg of parts per day. Since you are already a captive manufacturer with some of these personnel and services available, maybe it will be okay -- but if I were you I would investigate whether there is a barrel zinc plating job shop in your country :-)

Best of luck, and Regards,