Subrata Bhar

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Hello,
I feel myself proud to become a member of this metal finishing community. I have a small electroplating set up where we plate White Rhodium, Gold, Silver etc. on jewellery articles like Necklaces, Bangles, Bracelets, Pendants, Earring etc. We use nickle as a base metal plating on white metal objects. Nickle plating itself is very critical and do it manually often resulted in faulty plating thus resulting in a loss. Nowadays Nickle like other metals have become very costly it has become very tough to sustain in this heavily competitive field with this manually operated small plating unit. Is there any way to run base metal plating like Nickle, Copper in a uniform way that can produce excellent brightness and a good barrier layer to the objects being plated? Can anybody highlight on this matter? Please post your valued comments on this.
With warm regards and best wishes to you all.
Thanks
Subrata Bharsmile

DustinGebhardt

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

What are your common problems with the nickel plating?  If we know what your problems are, perhaps we can be of more help.

-Dustin Gebhardt,
CEF
Plating Engineer
Danaher Tool Group
Gastonia, NC

metfinoh

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Hello Subrata,

Welcome to the Finishing Talk Forum!  We are pleased to have you as a fellow member.  What is metal finishing like in Kolkata? Are there many other metal finishing - powder coating and plating shops in your town?  Do you have a metal finishing organization (club or association) that meets in your city? Does it have environmental laws and concerns as we do in the US?

http://www.finishingtalk.com/attachments/general-discussion/100d1203690469-i-am-subrata-bhar-kolkata-india-hello-you-all-picture1.jpg

As to your question..... I would look into White Bronze as a non-nickel replacement.  This is an old automotive plating process that is being resurrected to be used now because of the new European laws pertaining to Ni that touches the skin.  Carolina Process Control (CPC) is a member here and I know they have experience with that process.  You should message them.  Good luck and welcome.

Subrata Bhar

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Hello Sir,
I am very ill need to rest for more than a week. I will make a reply when I am fit. Anyway thanks for your reply. I will write to very soon. Thank you.

Subrata Bhar

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Hello sir,
I am very ill need to rest for more than a week. I will make a reply when I am fit. Anyway thanks for your reply. I will write to very soon. Thank you.

Carolina Process Control

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Hello Subrata,

We hope you get well soon!

http://www.carolinaprocesscontrol.com/i/t/logo.png

Carolina Process Control's Website

Subrata Bhar

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Hello Sir,
Sorry for being late. I had to undergo a treatment for which I was admitted to hospital and I could not answer you. Extremely sorry for that. First of all I need to thank you for your reply. Most common problem we face with nickle plating is to replenishing the solution. Usually we do it manually, we see the object being plated if we get a dull finish we start replenishing additive and brightner simultaenously by batch untill we get desired finish as you know we do jewelery plating we need that the finish must be appealing. Sometime we succed sometimes we fail. My question is : Is there any method or procedure to monitor the whole while plating and so as to replenish salt,boric acid, brightners so that we can get smooth bright finish all the time.
With warm regards
Subrata Bhar

DustinGebhardt

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

You can add your brighteners using several methods. 

You can use a Hull Cell or similar apparatus to monitor the bath's performance and when you notice that it is looking dull, you can test how much brightener needs to be added.  Once you have some history established, it becomes much easier to know how your specific bath is performing.

You can also see if you rectifiers have amp-hour totalizers.  You can calculate the number of amp-hours the bath has been run and make brightener additions using a known reference.  Most suppliers of plating chemicals can tell you how many liters/gallons of brightener to add for every X number of amp-hours.

An addition to this last method is very popular as well.  There are automatic feeders available that pump small quantities into the bath based upon amp-hours.  They require some initial work setting them up and also some routine calibration, but they are well worth it.

The second/third method works well for maintaining your brightener levels relatively constant.  However, it is always recommended that you under-feed your bath using this system.  Then you can always make additional over-the-side additions to fine tune your bath.

For making additions of salts, boric acid, etc, it becomes more difficult.  Many of the largest plating companies still use frequent analysis in a laboratory to determine the additions needed.  However, you can make routine additions of these products if you have a constant level of production and you know how much you have used in the past.  If, in the past, you have used 50 pounds of nickel chloride per week, then you could add 10 pounds every day for 5 days.    The disadvantages of this is that sometime you can run low or high, but in general you should run fairly well if your history is accurate.

-Dustin Gebhardt,
CEF
Plating Engineer
Danaher Tool Group
Gastonia, NC

Subrata Bhar

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Hello,
Happy to hear from you.You wrote to establish a history of a specific bath. But how can history of a specific bath can be established? Could you please elaborate the process?
Thanks
Subrata Bhar

Subrata Bhar

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

3

DustinGebhardt

Re: I am Subrata Bhar from Kolkata, India, Hello to you all.

Having historical iniformation of your plating process is a very useful tool.  If you know that once a week you make a large addition to your acid tank or your electrocleaner tank, you can easily divide that addition up over the span of several days.  This will help your bath become more stable.  For example, if the conecntration is good Monday through Thursday and requires a 5 kilo addition on Friday,  you could make 1 kilo additions every day and help stabilize the bath.  The more history you have of the process, the more accurate your additions can become.

The same principle applies to Hull Cells.  A Hull Cell is a good tool, but it never exactly mimics a plating bath.  However, over time you can discover that your bath performs just fine even when the Hull Cell is mediocre.  Or you perhaps discover that you must have extraordinary brightness in your Hull Cell to have acceptable results in your process. 

To establish your history, you must begin to perform your normal analysis and log the data.  You must also log the additions made to the bath, observations, etc.  Logging the amount of work the bath has produced is also a good idea.  Over time, you will begin to see patterns emerging.  Use those patterns to your advantage.  I usually start with a spreadsheet program like Microsoft Excel.  I begin entering the date, bath parameters(concetrations, temperature, pH, etc), work load, additions made, etc.  Or you could purchase a piece of software specifically designed for plating operations like TrueChem.  I'm not sure if it is available in you location, but you might want to look.

-Dustin Gebhardt,
CEF
Plating Engineer
Danaher Tool Group
Gastonia, NC