Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989





-----

Anodic alkaline cleaning and anodic acid etching





March 9, 2012

Q. Hi All,

I am considering utilising the following processes for a EP line where the parts to be processed are hollow 304 tubes with cutting geometries formed on one end through grinding and/or laser cutting:

1)Degreasing (coolant) using Anodic Cleaning in a caustic agent
Reason: I am concerned about coolant drying into the parts and also on the ability of ultrasonics to get up the tube (smallest ID 1/16"). The anodic action seems to send O2 bubbles up the tube.

2)Anodic Etching in a sulphuric (10%) electrolyte to remove Fe contamination and Laser cut dross
Reason: It is faster than immersion pickling and avoids HF and Nitric chemicals. I am concerned on attach to the 304 surface.

I would like to gain from other peoples experiences with the above processes both positive and negative

Alan Tobin
- Ireland


First of two simultaneous responses -- March 14, 2012

Anodic treatment in both, especially the alkali, will passivate (oxidize) the nickel on the surface of the 304. You need to finish up on the cathodic side to activate (reduce) the nickel oxide, then follow with a nickel chloride (Woods) strike.

robert probert
Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina
probertbanner



Second of two simultaneous responses -- March 14, 2012

Alan,

What is the ratio length/diameter?

anna_berkovich
Anna Berkovich
Russamer Lab
supporting advertiser
Pittsburgh, Pennsylvania
russamer labs banner



March 16, 2012

The ratio varies but 30:1 would be nominal.

Is it the anodic action which oxidises the nickel or the immersion in caustic?
Also if it wasn't deoxidised, what would the implications be post EP? Pitting?

Alan Tobin
- Ireland



March 22, 2012

Your plating process on 304 is wrong: try to use catholyte to degrease and activate surface, then deposit Watt's nickel, but the best strike plating bath is NiCl2 +HCl

kevin chiao
- Changsha, China



March 22, 2012

Hi, Alan.

You might spell out "EP" instead of abbreviating.

I initially thought you meant electropolishing, others obviously thought you meant electroplating, and now I'm thinking you mean electro-pickling :-)

Regards,

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



First of two simultaneous responses -- March 23, 2012

Alan,

Electro-Polishing is the best option. Or call it electrocleaning, since it took only one-two minutes to produce clean and deburred inner surface in our Universal electrolyte.

Simple degreasing without electrical current worked fine as preparation before electrocleaning.

anna_berkovich
Anna Berkovich
Russamer Lab
supporting advertiser
Pittsburgh, Pennsylvania
russamer labs banner



Second of two simultaneous responses -- March 24, 2012

Apologies for the confusion. I am referring to Electropolishing.
The 2 processes I have asked about are used for Pre cleaning. One for removing coolant and the other for removing laser dross.

Alan Tobin
- Ireland


none
finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully 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 might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact    -    Privacy Policy    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA