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

HomeFAQsSuggested
Books
Help
Wanteds
Advertise
on this site
FORUM
current topics
Live! From beautiful Pine Beach New Jersey: Welcome to the world's most popular metal finishing website

topic 54294

Nickel sulfamate pitting problem

adv.
nickel how-to book


"The Sulfamate Nickel How-To Guide"


by David Crotty, PhD
& Robert Probert


Hot Off the Press -- published Oct. 2018
$89 plus shipping



February 6, 2010

Q. Our customer is experiencing pitted nickel deposits from a proprietary nickel sulfamate bath. The bath is a new make up. The parameters are as follows: Nickel metal- 15.5 oz. per gallon, nickel chloride 0.1 oz. per gallon, boric acid 5.5 oz. per gallon and pH 4.1, temperature 140 °F. The plating line is reel to reel plating on carbon steel wire using S round nickel anodes in titanium anode baskets. The cd is approx. 60 asd. The plating tank has air agitation and gravity overflow from the wire passes on each end of the tank. The pits have no visible tail and are concentric circles. There is no wetting agent in the tank since earlier testing using a beta cell indicated it was not necessary. The pre-treatment is an alkaline soak clean, alkaline electroclean and sulfamic acid salt with appropriate rinses. The line speed is 18 meters/minute and the wire is about 3/4" from the anodes on both sides. We increased the boric acid 0.5 oz. per gallon and lowered the pH to 3.9 and the problem got worse. Does anyone have suggestions besides the obvious adding wetting agent? We can do the WA test in a Hull Cell. Thanks.

Doug Trageser
- Chattanooga, Tennessee USA


simultaneous February 9, 2010

Doug,

A couple of suggestions

1. The drag in from the sulfamic solution might be high. this would cause the nickel plating efficiency to drop where the wire first enters the nickel station and cause some gassing that can lead to pits.

2. The boric acid could be too high. When the cold wire enters the nickel tank the boric acid can crystallize out on the wire. The boric is non conductive which will also lead too pits

3. It might be that a wetting agent is needed. Hard to duplicate a high speed reel to reel process in a hull cell.

Pat Mentone
Pat Mentone
St Paul, Minnesota


February 9, 2010

A. Hi Doug. Commercial nickel sulfamate in the last 15 years has not been dummied and carbon treated to the extent that the old popular trade name had been treated. Even with perfect sulfamate concentrate with use at your higher temps and higher c.d., breakdown product from the SN and from the S-rounds lower the efficiency and then the hydrogen starts to cling to the cathode. In the real world without continuous dummying and continuous sulfur free carbon it is virtually impossible to operate without a surfactant.

robert probert
Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina
Editor's note: Mr. Probert is the author of Aluminum How-To / Aluminio El Como
and co-author of The Sulfamate Nickel How-To Guide



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.