metal blackening

2 comments

Rate

moonlight Associate Join Date: Jul 2008 Posts: 35	metal blackening 08/08/2008 5:18 AM
	how can a cast iron to turn their surface black thru black oxidation.is the free graphite in structure is responsible for color to come. actually we need black in cast iron.so how it will come.
	Register to Reply
	Pathfinder Tags: blackening electroplating metal coloring Plating

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!

PWSlack Guru Join Date: Jan 2007 Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on. Posts: 32175 Good Answers: 839	#1 Re: metal blackening 08/08/2008 8:46 AM
	Oxidised graphite is carbon dioxide, which is a gas at everyday temperatures and pressures. So the black colour has to come from something else. Carr's "Metal Black" (usual disclaimer) works on steel. It can be located in all good model shops. __________________ "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
	Register to Reply

techno Guru Join Date: Jan 2007 Location: Canada Posts: 1024 Good Answers: 40	#2 Re: metal blackening 08/08/2008 10:16 AM
	There are many chemicals that patina metal. Some oxidize, Some create a chemical reaction that changes the chemical composition of the surface of the metal. It is important to thoroughly rinse the metal after application of the patina to stop the chemical reaction. Some are very hazardous. We patina copper all the time. The best and safest source I have found is JAX __________________ Perfection is a subjective and abstract concept.
	Register to Reply Score 1 for Good Answer

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!

	Got Something to Say?
	Ask a Question Start a Discussion

	Aerospace
	BioMech & BioMed
	Chemical & Material Science
	Civil Engineering
	Communications & Electronics
	Education and Engineering Careers
	Electrical Engineering
	General Discussion
	Instrumentation
	Manufacturing
	Mechanical Engineering
	New Technologies & Research
	Software & Programming
	Sustainable Engineering
	Transportation

	Site Directories
	Forum Directory Blog Directory User Group Directory RSS Feeds CR4 Rules of Conduct CR4 FAQ Site Glossary Who's Online (87 right now) Show Members