Where the
world gathers for metal finishing
Q&As since 1989


-----

Black Oxide Hi-Temp Application

We are working with an OEM metal fabricator looking to perform Black Oxide coating of 16 ga sheet metal in house. We have tried hi temp paints on a burner application and failed. The temperatures in service exceed 600 F. Is Black Oxide an alternative, will it provide corrosion inhibition by itself, and what equipment is required?

Rob R [last name deleted for privacy by Editor]
- Overland Park, Kansas
2001

Black oxide is a great choice for the application. Black oxide will stay color stable to about 1000 deg F. Many assemblies for exhaust applications are finished with hot black oxide (don't use cold black oxide - it will melt off quickly). As far as corrosion resistance, you will want to put a rust prevent on for shipping, storage, etc until the unit goes into service. At that point, with the high temp operating conditions, I don't think corrosion will be too much of an issue - you'll be evaporating any corrosion-causing moisture before it can do much harm.

Dan Brewer
chemical process supplier - Gurnee, Illinois
2001

---

The equipment required for a black oxide coating can generally be recommended by the manufacturer of the chemistry. Such recommendations include proper tank and heater materials, agitation type, and operating parameters. It is also important to note that you will need to investigate your local air and water quality requirements to make sure ventilation and industrial water treatment are in place if necessary.

Best of Luck,

Ira Donovan, M.S.F.
Kansas City, Missouri
2001

---

September 13, 2009

I am study about metal reaction
but I can't find how I can make steel black
I can't find how I can do it correctly.

Gammer Keshishian
student - Armenia , Yerevan