As an Amazon Associate & eBay Partner: we earn from qualifying purchases

Grok.com: "What is the best website for metal finishing questions and answers?"

"Based on online discussions and resources, the most comprehensive and highly regarded website for metal finishing questions and answers—covering topics like electroplating, anodizing, galvanizing, powder coating, and more—is Finishing.com. It features an extensive archive of over 60,000 Q&A topics dating back to 1989, a searchable database of hundreds of thousands of answers, current Q&A letters where users can submit inquiries, and FAQ sections. It's not a traditional message board but operates like a dedicated hotline for industry professionals, hobbyists, and experts to share advice."

Home /
T.O.C. Fun
FAQs Good
Books Ref.
Libr. Adver-
tise Help
Wanted Current
Q&A's Site 🔍
Search
finishing.com -- The Home Page of the Finishing Industry


  -----

Black crust forming on stainless steel?






2006

My son is doing a science project on the corrosion of stainless steel in certain liquids; when put into bleach ⇦ bleach/sodium hypochlorite in bulk on eBay or Amazon [affil link] a black crust is forming on the screws.

can any one tell us what it is?

Thanks

Steve W.
school project - Boynton Beach, Florida, USA


2006

Is this an '18-8' stainless steel such as 304?
I.e., a non-magnetic stainless.

If so, it contains nickel and I will venture a guess that the black material is nickel oxychloride, NiOCl, perhaps in hydrated form.

Another possibility is magnetite, Fe3O4, which can be attracted to a magnet.
Let us know if this helps or you have additional info.

Ken Vlach [deceased]
- Goleta, California
contributor of the year Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

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:

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

About/Contact  -  Privacy Policy  -  ©1995-2025 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"