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

HomeFAQsSuggested
Books
Help
Wanteds
Advertise
on this site
FORUM
(current
topics)
topic 8308

Dirty Anodes in our Copper Sulfate Bath


(2001)

We are plating electroless nickel on titanium. The problem seems to be with our copper strike. The copper is not throwing into low current areas. We are running current densities around 35 ASF. The copper strike is a copper sulfate tank, consisting of 7 oz/gal copper sulfate, 7 oz/gal sodium hydroxide, and 24 oz/gal rochelle salt. The bath checks out OK chemically. The copper anodes in the tank look terrible. They are covered in a bluish-purple film that takes a Scotch Brite [linked by editor to product info at Amazon] pad to remove. When the film is removed, it has the appearance of a ultra fine rust colored powder. The film builds up if we leave the anodes in the tank with no current.

Help! We are absolutely stumped!

Chris Mance
- Tinker AFB, OK


(2001)

I have never seen a copper sulfate bath with sodium hydroxide. Maybe look in your guide book at a sulfuric/sulfate make up?

Todd Huehn
- Minneapolis, Minnesota



(2001)

The alkaline copper bath is the one called for in our Technical Order. We've been using it for years without this problem. The bath works great, just not since last week.

Chris Mance
- Tinker AFB, Oklahoma


(2001)

Hi Chris.

I think the anodes are polarised, clean them up or try a new one. Maybe you have use to high current density.

Regards

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





March 2, 2011

This is a follow-up to the unresolved issue in letter 8308.

We must use a non-cyanide rochelle copper strike. Copper (I) oxide powder builds up on the anodes and outside the anode bags and sloughs off to the bottom of the tank, gradually reducing tank depth. We never remove our anodes from the plating tank - the copper in solution is apparently reacting with the oxygen from the electrolysis of water.

Is this preventable or reversible? Will adjusting anode surface area reduce this phenomenon?

Adding cyanide is not an option.

Art Campbell
Process Tech Support - Oklahoma City, Oklahoma, USA



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.