asad.ilyas

Topic: Zinc Plating bath control ?

I currently use a solution of  Zinc Cyanide with Caustic Soda for the electroplating bath. As the bath gets used the chemicals get depleted.

Is there a way that I can measure the chemicals or in other words, mantain or analyze the balance of the bath ?

asad.ilyas's Website

SFA

Re: Zinc Plating bath control ?

Hello Asad,

I found an Analysis sheet for a cyanide zinc product manufactured by Luster-On Products.  Rather than retyping it I will post it below as a pic.  Hope it helps.


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Surface Finishing Academy
www.surfacefinishingacademy.com
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SFA

Re: Zinc Plating bath control ?

And also - if you are using this product and your supplier has not supplied this info for you, and taught you how to do the analysis - you should seriously consider changing suppliers.  If this is the case - I suggest you speak with Luster-On - they would never leave a client in this position.


Surface Finishing Academy
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Rence

Re: Zinc Plating bath control ?

Hi,

You should check it with your chemical supplier on this. They should have the analytical methods to do. If they don't have or don't want to share with you, you may find a more reliable chemical supplier.

If you don't check or maintain your bath regularly, you will find much trouble on the plating quality in the future.

GeoffPW

Re: Zinc Plating bath control ?

I am always amazed when I see control methods given where the titrating solutions are not common standard solutions.
Platers can not make  accurate titrating solutions with the info given and you can purchase accurate Standard solutions from laboratory supply houses.
examples above are silver nitrate 13g/l (.076N) instead of 0.1 N
0.94N sulphuric acid instead of 1.0N. I guarantee that no plater can accurately add 26.2 ml per litre and get .94 N
EDTA is it 22.34g of Na2, Na3 or Na4.
If you don't have an accurate standardized solution to titrate with you can't get the correct answer and all you need is a different multiplying factor as in the case of Sodium Carbonate where the titrant is 1.0N HCl and a factor of 0.71.


Daniel

Re: Zinc Plating bath control ?

Cyanide zinc baths are among those with less control, they can operate with huge amounts of grease and if they are contaminated with copper  the deposits are not white, they became yelowish some book reports operating to 60% of oil(i cant believe it) so usually the operators just add zinc oxide, brigthener and purifier. and remove the sludge from the bottom of the tank often.

Chemical analisys is left to the supplier, how is your bath do you use zinc anodes?, steel anodes?.