Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Green oxide on copper plated bars

Green oxide on copper plated bars

Green oxide on copper plated bars

We use pre-plated silver plated copper bars, on the edges it is bare copper.  This can develop a green oxide over time.  Could this hurt anything, can it creep into the silver plated areas?

Mark Faulkner

RE: Green oxide on copper plated bars

Yes, the green patina* is a corrosion product that could undermine the silver plating.

Possible solutions for the exposed areas: Brush plating of silver, brush plating of tin, application of plastisol (brush-on vinyl in a solvent), application of grease or wax (I prefer Alcoa’s Electrical Joint Compound (EJC) No. 2), or painting.

*the green patina is not an oxide; it consists of malachite (basic copper carbonate, CuCO3Cu(OH)2) and usually lesser amounts of brochantite (basic copper sulfate, CuSO43Cu(OH)2) and atacamite (basic copper chloride CuCl23Cu(OH)2).

The copper oxides are the red cuprite, Cu2O, and the black tenorite, CuO.

RE: Green oxide on copper plated bars

I was told this green patina was a super conductor...yea, by another engineer! I don't think so.  I believe this will increase the resistance of a joint and cause heating.  If I had this corrison on the edge of a bar, would it spread on other plated areas or is it local.

thanks in advance

RE: Green oxide on copper plated bars

Super conductor??????????  told…by another engineer??????????
Check whether he majored in humor.  
Of course, you could sinter the copper compound with Y2O3 and BaO in the right proportions to create the ‘1-2-3’ superconductor, allowing a much smaller busbar (provided it was kept in liquid N2).

Yes, of course it will increase the resistance.

Yes, it will undermine and lift off the silver plating.  Since silver is galvanically noble to copper, the reaction may be more rapid at the interface.

Is the silver tarnished?  If not, perhaps it was chromated or lacquered.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


White Paper - Strategies to Secure Connected Cars with Firewalls
White-hat hackers have demonstrated gaining remote access to dashboard functions and transmissions of connected vehicles. That makes a firewall a vital component of a multilayered approach to vehicle security as well as overall vehicle safety and reliability. Learn strategies to secure with firewalls. Download Now
White Paper - Model Based Engineering for Wire Harness Manufacturing
As complexity rises, current harness manufacturing methods are struggling to keep pace due to manual data exchanges and the inability to capture tribal knowledge. A model-based wire harness manufacturing engineering flow automates data exchange and captures tribal knowledge through design rules to help harness manufacturers improve harness quality and boost efficiency. Download Now
White Paper - What is Generative Design and Why Do You Need It?
Engineers are being asked to produce more sophisticated designs under a perfect storm of complexity, cost, and change management pressures. Generative design empowers automotive design teams to navigate this storm by employing automation, data re-use and synchronization, and framing design in the context of a full vehicle platform. Download Now
eBook - Simulation-Driven Design with SOLIDWORKS
Simulation-driven design can reduce the time and cost of product development. In this engineering.com eBook, we’ll explore how SOLIDWORKS users can access simulation-driven design through the SOLIDWORKS Simulation suite of analysis tools. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close