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"Acid Zinc Plating Roughness"
Current question:September 29, 2021 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. Hi there!, guys our company is about to open an acid zinc electroplating plant so here we are trying to get information about the system. The question is how important is a filter system to clean out zinc bath, what is more important, salt precipitates or organic traces? Do we really need activated carbon filter or it could damage the action of the organic brighteners?
Thank you all!
- Sinaloa, México
A. Hi Jorge.
Yes, filtration is essential to remove metal fines, salt precipitates, shop dirt, iron, precipitated boric acid, kicked-out carrier/wetter, etc.
As for carbon filtration and organics, primarily you should rely on what your supplier says because, although carbon filtration can remove brightener breakdown products, some addition agents can be inadvertently removed by carbon filtration. Further, simple continuous carbon filtration may be insufficient to remove a build-up of undesired organics, and you will probably need periodic permanganate oxidation and batch carbon filtration.
Please search the site for "acid zinc filter" for a number of good discussions on the topic (Google prohibits us from 'preloading' search terms into their search engine for you).
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Closely related Q&A's, oldest first:2004
Q. I am in charge of an electroplating facility that provides zinc electroplating (acid chloride) service to our customers. One of our customers recently rejected our components due to roughness of the surface. We are suspecting that poor filtration or a high boric acid might be responsible for causing this roughness. We are still getting components with roughness and looking for ways to resolve it. Any comments will be highly useful.Prabha Samuel
Electroplater - Chennai, Tamilnadu, India
A. If you have more roughness on the top, (as plated)it is definitely a filtration problem. A simple analysis will tell you if you have a boric acid problem or any other chemical imbalance. You might have magnetic parts holding some very fine particles to the part. Fix the problems one at a time and you will find out which one was the cause of your rejects.James Watts
- Navarre, Florida
A. Ms Samuel,
Continuous Filtration is necessity number one for acid zinc Plating. You need che ck pH is not higher than recommended. Older systems run well at 4.4 ,,, 4.6. The new Generation systems accept air agitation and work really well at 5.4 pH. The roughness experienced must be attended to with a filter.
Asif Nurie [dec.]
- New Delhi, India
With deep regret we sadly advise that Asif passed away on Jan 24, 2016
A. Ms. Samuel,
Indeed, you have a filtration problem. Check the filter, first, your boric acid pH second.Joel Garcia
- McAllen, Texas
A. PRACTICALLY I HAVE NOTICED THIS TYPE OF PROBLEM,
COVER ZINC ANODE WITH P.P BAGS
USE GOOD QUALITY PADS IN FILTER
USE GOOD CHEMISTRY
Ludhiana, Punjab, India