finishing.com -- The Home Page of the Finishing Industry
23+ years of serious education, promoting Aloha,
& the most fun you can have in metal finishing smiley
    no popups, no spam
HomeFAQsSuggested
Books
Help
Wanteds
Advertise
on this site
FORUM
current topics
topic 5370

Autocatalytic Ni/P - Precipitation


2000

I am looking for some tips on eliminating nickel precipitation from autocatalytic Ni/P bath. We are not a plating shop but we do very small batches of Ni/P for our own purposes and often the Ni precipitates even before parts are processed. We monitor quality of DI water, pH, bath is run through filters, etc. Where shall I start looking for the root cause ? ... . I'd appreciate some tips. Mariusz de Georgel

Mariusz de Georgel
- Toronto, Canada


2000

Firstly, how often are you using the NiP? If you have it at operating temperature a lot but are not using it often, this can easily cause precipitation. Secondly, what kind of tanks are you using, and have they been properly prepared? They need to be leached before initial use and then passivated with 30% nitric acid followed by neutralisation with ammonia or potassium carbonate solution before refilling with solution. What type of heaters do you use? If they are 316 stainless steel they need to be passivated at 40 °C in 30% nitric. And how is the temperature controlled? If the temperature regularly gets above the maximum operational point (usu 90-93 °C), precipitation may readily occur.

John Reid
CP Plating - Brisbane, Qld, Australia



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 Comment 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


©1995-2018 finishing.com, Inc., Pine Beach, NJ   -   About finishing.com   -  Privacy Policy
How Google uses data when you visit this site.