finishing.com -- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

HomeFAQsBooksHelpWantedAdvertiseForum
(current
topics)
topic 3997

White milky areas during Nickel plating


(1999)

Dear Reader,

We plate die-cast Zamak parts. (Copper Nickel -Watts bath-, and chrome). The problem we are having is that in (during) the Nickel bath white, milky areas appear on the surface. They look like the "classical" Chrome burn (Flash) but are not in the HDC areas. Another characteristic is that the spots are extremely smooth to the touch. Has anybody had similar problems and who could give me a clue as to what could cause these "misplates"?!

andreas gengenbach
- Venezuela


(1999)

Hi Andreas ,

What you are describing is typical of an overdose of brightener , in the current systems each supplier has a "Corrector" for Organics , try this at their recommended concentrations , if it does not IMMEDIATELY fix the problem then the answer is too much "Trace Heavy Metals" and you will need to Dummy plate with corrugated cathode at a current density of 2 amps / square foot of cathode area .

Best regards

John Tenison-Woods
John Tenison - Woods
- Victoria Australia


(1999)

Hi Andreas

I am assuming that the white, milky haze can be seen before chromium plating. We have seen this condition a couple of times lately and in every case, the plater had put new anode bags on his anodes. If you have changed your bags just prior to the condition occurring, this is probably the cause. Continuous carbon filtration is the corrective measure.

There are other conditions that can produce a milky haze and to expedite a solution, sending a sample to your supplier of additives is the best solution.

Regards

Ken Lemke
Ken Lemke
Burlington, Ontario, Canada


(1999)

Unfortunately, I'm afraid John is right, this has happened to me on more than one occasion and each time it was too much brightener. One time the problem was so bad that we had to filter the entire bath out and back in again using activated charcoal. This did remove all of the brightener and wetter.The key was white streaking out of the nickel bath prior to chrome, impurities typically were seen as dark in LCD areas.

Ward Barcafer, CEF
aerospace - Wichita, Kansas



This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView CURRENT 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


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.