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


  -----

RED FINISH ON BLACK OXIDE




I AM OPERATING A 200 GAL HOT BLACK OXIDE TANK AND CONTINUE TO EXPERIENCE A RED FLASH RUST ON THE SURFACE OF THE PART WHEN THE PARTS ARE MOVED FROM THE BLACK TANK TO THE RINSE TANK.THE PART ACTS AS A HEAT SINK AND WHEN DIPPED TO RINSE IT HAS A QUENCHING EFFECT. OPERATING TEMP IS 280-290F AND TRANSFER TIME IS ONLY SECONDS. WE ARE HAVING TO HAND RUB EACH PART TO REMOVE THIS REDDISH FINISH . WE HAVE CLEANED OUR TANKS BUT ARE STILL SEEING THIS SMUT! ANY SUGGESTIONS?

DAN MORPHEW
- COOKEVILLE,TN
2000



Got a suspicion...only that. Wonder if you use tap water to make up this bath? Tap water contains Chlorides, and you evaporate off a lot of water, I suspect, and I wonder if the Chlorides are causing this flash rusting?

Chloride has such a profound effect on all of metal finishing, that it always is a suspect, especially when corrosion is occurring.

Rudy Sedlak
Mountainview, California
2000



Dan -

It sounds like your parts are too hot, causing the iron freeze. Another cause could be that your tank needs rectifying - it has too much insoluble iron in it. Be sure to skim it every morning too - this will take out the floating iron when the bath is below it's operating temp.

Dan Brewer
chemical process supplier - Gurnee, Illinois
2000




(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"