finishing.com -- The Home Page of the Finishing Industry

HomeFAQsSuggested
Books
Help
Wanteds
Advertise
on this site
FORUM
current topics
The world's most popular metal finishing site, and the internet's friendliest corner

topic 35342

White patches in Chrome Plating


A discussion started in 2005 but continuing through 2019

2005

Q. We get white patches on some of the parts we plate. What causes this to happen?

Bill Blondick
plating shop - Chicopee, Massachusetts


simultaneous



simultaneous



simultaneous



2005

A. Just on the edges is burning from excess current; but you'd recognize that. All-over is current interruption during chrome; check condition, cleanliness and tightness of all contacts. If spots and splotches in random pattern, it's passive nickel; check for drying between nickel and chrome, grease films on rinses or chrome tank, try to improve rinsing with warmer water or better agitation or longer time or add another rinse. Maybe excessive nickel brightener, try soak for 15-30 seconds in chrome before applying current.

A thousand other possibilities too. Tell us more, when how, what does it look like?

jeffrey holmes
Jeffrey Holmes, CEF
Spartanburg, South Carolina


2005

A. You have Excess Sulphate in your bath in excess of 150:1 Chromic acid: Sulphate.
Please get your Sulphate content analysed and adjusted.
You can use Barium Carbonate to reduce Sulphate content.
Also maintain Chromic Acid conc. around 320 grm/litre Minimum.

t k mohan
T.K. Mohan
plating process supplier - Mumbai, India


2005

A. Bill,
White patch in chromium bath, you have to describe your problem in detail. The white patch means white wash or stain or chrome burn?
All are different answers. If it is white wash do you have chrome predip before chrome tank? Bipolarity -- falling parts in tank touch to working bar parts in chrome & nickel tanks or activation problem. Chrome burn - check current , rectifier ripple and chrome temperature , stain -nickel passivation or high brightener in your nickel tank.

popat patel
Popat Patel
    Beacon Park Finishing LLC - Roseville, Michigan


2005

A. Your nickel has become passive.

This can be from a myriad of reasons
High brightener- Stop brightener additions until nickel dulls
Organic contamination- carbon treat
Dirty rinses- replace and keep mildly acidic
Bi polarity causing the nickel to become anodic in certain circumstances

To keep in production until problem solved, activate nickel in cathodic acid or cyanide. Sometimes activation in dilute chromic acid helps.

Geoffrey Whitelaw
Geoffrey Whitelaw
- Port Melbourne, Australia


2005

Q. To detect chrome burns on a chrome rim...what is the best type of light to use that will make the burn stand out making it easy to detect at an inspection station...

Type of light, kelvin, wattage, etc.

Thank you

Rick Pope
Electrical - Kitchener, Ontario, Canada



April 17, 2013

Q. We are plastic part platers. We have white patches/shadow on the part after plating in the Bright chrome (Cr6). For corrective ACTION, we had tried to change the predip solution regularly before chroming process, control the sulphate content in chrome & predip chrome tank, and mix some sulphuric acid in the dragout tank after nickel plating. However,the problem still exists.

Is this problem related to too much wetter in Nickel plating? Or is it due to traveling time that been taken to long between nickel to chrome process making the nickel layer passivate? Or is it related to our DI water pH/quality? Anyone with new idea/suggestion, please help. Thank you.

Norddin Norddin
plating company staff - Malaysia


April 25, 2013

A. Hi Norddin,

Non uniform white patches could due to:

1. Lead contamination in chrome bath.
2. Poor cleaning prior nickel plating.
3. Part dries prior to chrome plating.

Regards,
David

David Shiu
David Shiu
- Singapore



December 23, 2014

Q. Dear all,
Here what all factors which causes white patches are really found, but is there any effect of semi-bright nickel for white patches? Please help me to sort out this problem and to know about it?

CHANDRASHEKHAR NAVILE UMAMAHESH
- bangalore, karnataka, india


"Nickel and Chromium Plating"
by Dennis & Such
from Abe Books
or
info on Amazon

December 2014

A. Hi Chandrashekhar. Sorry, I'm not sure if I'm fully understanding your question. Are you saying the patches form in the semi-bright nickel plating step, but then you go on to bright nickel plating and chrome plating and you can still see them after the other plating steps? Apologies, but I don't quite understand your situation. Please spend several paragraphs on details. If you can include pictures I'm confident that the readers can help you address it. Thanks!

If you are seeking a general discussion of nickel plating issues, like what effects the semi-bright nickel step can have on the final nickel-chrome plated object (with all the ifs, ands, & buts), here is a nickel plating book which should help. The "The Canning Handbook" style= [link is to info about book at Amazon] has a good troubleshooting section on nickel plating too. Good luck.

Regards,

Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E.
finishing.com - Pine Beach, New Jersey
Striving to live Aloha



February 11, 2015 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. Sir, I am working for a rotogravure cylinder manufacturing unit. First time I am facing the problem of "whiteness" in chrome plating. Whenever I start going to flow the current onto the object, it creates big patches and the patches all convert into whiteness on complete cylinder. My chromic acid is 260 gm/lt and sulphate is 1.8 gm/lt. Please suggest what should I do for this?

Gaurav shah
gravures - hyderabad,Telangana,India


February 19, 2015

A. Hi Gaurav,

The problem could due to:

1. High pH
2. Low wetting agent
3. Low chrome concentration
4. Lead, zinc contamination
5. Poor cleaning before plating
6. Parts dry up prior chrome plating

Regards,
David

David Shiu
David Shiu
- Singapore



April 14, 2015

Q. Hello. I send some photos with white patches on our plated parts. Is this white wash or what is this? Usually it goes away when I add some brightener and wetting agent.

35342-1a  35342-1b  35342-1c

Can anyone tell me what are this white spots on the photos I attached?

Bojan Koren
- Bovec, Slovenia


April 25, 2015

A. The rinses between nickel and chrome contain inorganic contamination.

Regards,

anders sundman
Anders Sundman
3rd Generation in Plating
Consultant - Arvika, Sweden



May 1, 2015

A. Check the sulphate ratio. It is common when sulphate ratio is high in the bath.

KP

Karthikeyan Ponnusamy
- Bangalore, Karnataka, India


May 2, 2015

thumbs up signThank you for your opinions but I think it's something wrong in the nickel bath because when I add 0.1 mL/L of brightener and/or some wetting agent the white spots usually disappear. We have problems with these white patches only on bright nickel not on matte nickel.

Bojan Koren [returning]
- Bovec, Slovenia


June 29, 2015

A. I have a strong feeling that the bright plating tank/vat may be contaminated with oil hence these patches. Please use scum remover, or use filter paper and swipe over the top of the tank, and use carbon treatment more periodically. Best regards.

Mahendra gargatti
- Belgium Karnataka lndia


August 16, 2015

Q. Dear Sir,

We are facing problem of white patch also. I think problem is generated from semi bright. Because in semi bright, the component is getting bright instead of dull. What can be the reason, please explain?

Neelanjana Bhattacharjee
- bhuj, Gujarat, India



May 28, 2016

! I have seen white staining on chrome plated parts as well. Chemical analysis revealed that they contained lead (Pb) and antimony (Sb) but in particular always Sb. Pb only stains were black. I believe these are contaminants from the anodes used which are commonly made from Pb-Sb alloys.

Hope this helps.

Lawrence Cheung
- South El Monte, California, USA


May 2016

thumbs up signHi Lawrence. Tin-lead and antimony-lead anodes were successfully used for chrome plating in thousands of shops for decades before I entered the industry, and that was 50 years ago -- so I would be shocked if they are the cause of white staining ... but I can't argue with your findings.

There may be something wrong with today's anodes or something unusual about your situation. Thanks for the thought-provoking idea !

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Striving to live Aloha


May 31, 2016

A. Good day Lawrence.

This white staining reminds me of "white wash". We could buff it out. In my experience, this "white wash" was attributed to organics carried over from bright nickel, and passivation of the nickel plating. High wetters/brighteners are difficult to rinse, and you need to avoid passivation of the nickel plate. I have used a nickel drag out tank, and kept the pH acidic, in an effort to simulate an acid dip. The drag out was sent to waste treatment weekly, as our sludges were sent to refining = $$$$$ in nickel metal. Also, I used the chrome drag out before chrome, but this drag out needs to be also kept clean. Are you using silver oxide? Are you adding barium carbonate as a slurry in water before adding to the chrome?
Just a few thoughts.

Regards,

Eric Bogner, Lab. Tech
Aerotek Mfg. Ltd. - Whitby, Ontario, Canada



Water mark issue on chrome surface

June 18, 2017 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. We are getting water mark on the chrome plating surface after chrome bath in POP, also sometimes we are getting tiny crack lines on plating surface. Please suggests possible solution to this problem.
Thanks in advance

Sanjay Khadse
Exotech Zanini Industries P. Ltd - Pune


June 2017

thumbs up sign  Hi Sanjay. Please send pictures to for posting here. One person's "water mark" can be another person's "whitewash", someone else's "patches" and yet another guy's "skip dots". Thanks.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Striving to live Aloha



White layer beneath nickel chrome plating

December 21, 2018 -- Actually posted July 19, 2019
Q. We are currently getting a hazy layer on our components which is very clear after plating, due to which we are not getting mirror finish.
We get this problems on about 50% of total components loaded on a single flight bar.
We do decorative Nickel & chrome plating.
Our bath composition have returned fine.
The same material if replating is done, the layer seems to go away.

January 23, 2019 -- Actually posted July 19, 2019
Q. We are getting a whitish layer on our components after nickel chrome plating.
This we get on 50% of our parts.

May 25, 2019 -- Actually posted July 19, 2019
Q. We are getting a uniform whitish layer beneath our Bright nickel & Chrome Plating.
The layer comes off in two cases
1. When we buff the components after plating (but we cannot as it compromises our chrome plating)
2. When prior plating we dip the Components for a minute in Hydrochloric acid (cannot be done for all components compromises Production)

July 19, 2019
Q. We are getting white patches on our components after bright nickel chrome plating.All our impurities are within range, we have chrome activation prior to chrome plating after nickel.

35342-2c   35342-2b   35342-2a  

The problem is that we are getting white patches after bright nickel plating. Our bath chemistry is fine, all impurities are within limits, brightener, leveler concentration level is also within prescribed range. (All we had checked with our present & previous Chemical Suppliers) Our Process is : Soak Degreasing - anodic cleaning - acid pickling (H2SO4 + HCl) - Anodic cleaning 2 - Acid Dip (H2SO4) - Strike Nickel - Semi Bright Nickel - bright nickel - Cr activation - Chrome Plating.
Please need help on above situation.

Yogesh Jha
EMPLOYEE - PUNJAB INDIA


July 20, 2019

A. Hello Yogesh,
When you say the impurities have been checked, would that be metallic impurities only? As you may know basic analysis will give you bath constituents, and 3 or 4 metallic impurities such as copper, lead and zinc. Organic impurities are normally not analyzed in routine bath analysis. When was the last time the bath was carbon treated? The last shop I worked for we would carbon treat when the bath turned a dark green color. Leave a bath sample of the untreated bath aside, then draw another sample after 4-6 hours of carbon treatment. The treated beaker sample should produce a clean emerald green color that is fairly translucent. You will notice a big difference in the color and clarity. Our supplier nor independent labs we worked with could not give us organic impurity levels because they were not set up for it. The second possible cause I would investigate would be the wetting agent concentration. If you do carbon treat consult your supplier so they can advise you of any additions to be made before you begin plating. The carbon treatment can pull out important organic ingredients. Hope this helps.

[But] I have to say I am totally confused with your post. You state you are getting the whitish haze after nickel and chrome, same effect under the nickel and chrome, and also after nickel plate. Where are you actually seeing the haze?

Mark Baker
Electronics plating - Winston-Salem, North Carolina USA


July 27, 2019

Q. Thanks Mr. Baker for your suggestions.

We have already carbon treated our bath when we faced such problem. To have a clear picture of our problem I have posted pictures in last thread.

We have noticed one thing that the problem is not all on components as sometimes we get 30% material ok and sometimes we get 70% ok but never 100%.

We tried out Hull Cell also but results were absolutely fine. We have chrome activation prior to chrome plating so this is not passivation I guess.

Please provide some help.

Yogesh Kumar [returning]
SHOP EMPLOYEE - PUNJAB INDIA


July 2019

thumbs up sign  Hi Yogesh. You did indeed post pictures, but I think the problem Mark references is that but your postings seemed to imply that this whitish look was present earlier in the process, possibly before any plating, or possibly after nickel plating but before chrome plating.

Can we call that a misunderstanding, say that the pictures are all after chrome plating, and that you do not have evidence of any whitish look until the wrenches are chrome plated?

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Striving to live Aloha


July 29, 2019

Q. Sir,

The pictures I have attached are after bright nickel chrome plating.
All I want is to remove this whitish appearance i am getting, as it is causing a lot of problems.

We have noticed one thing that if prior to plating process we Dip the samples in 10% Hydrochloric Acid and Load material for plating (that is regular process from cleaning till final) we get absolutely fine results.

Yogesh Kumar
Shop Employee - Punjab India



If you have a question in mind which seems off topic, please Search the Site

ADD a Q, A, or Comment on THIS topic START an UNRELATED topicView CURRENT HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices


©1995-2019 finishing.com, Inc., Pine Beach, NJ   -   About finishing.com   -  Privacy Policy
How Google uses data when you visit this site.