No passwords, no registration, no paywalls, no popups, no AI

As an Amazon Associate & eBay Partner we earn from affil links

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

Search our quarter-million Q&As

Home of the finishing HOTLINE since 1989

-----

Iridite coating in contact with silver plating

2005

Good morning

In the case of an Aluminum Plate that got an Iridite coating in contact with Silver plated Aluminum plate in presence of moisture and moderate heat generate a galvanic cell or chemical reaction over time? There is evidence of gray powder in the contact area.

Thank you

Dow Firnberg
- Rockleigh, NJ

Silver is on the positive side of hydrogen. Aluminum is very negative to hydrogen, therefore you have a real strong galvanic cell. However, the chromate should offer some protection. Incidentally, the same formula of Iridite is used for aluminum AND silver. But once the chromate is scratched or otherwise removed, and the moisture comes in, you will have corrosion, and aluminum and silver form gray colored corrosion producrts.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2005

Sorry! Finishing.com is temporarily Read-Only.
Ted Mooney is retiring but I have several offers to take it over.
We're working hard to make sure we find it the best new home.

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: