# Communities > Bladesmiths, Blacksmiths, Artisans and Professionals > Japanese-Style Sword Makers Cafe >  Patination and the resulting gases.

## Brian VanSpeybroeck

I'm not sure this is a question for this forum, but it really isn't blade oriented so here goes! :Big Grin:  

I have set up a tank in the basement for patinating steel sword fittings. I am trying several different techniques from slow rust bluing to immersion in ferric chloride and holding at around 120 degrees F or so. I'm using a heat lamp and a glass aquarium with a loose fittting lid and a heat lamp. *REAL* nice dark blue/black oxide is being formed by immersing the steel piece in vinegar and then just setting the vessel holding the steel in the tank. I can see the bubbles rising in the vessel and then wondered if the gas is inert or toxic. Would this be carbon dioxide? Or could it be hydrogen or something else flamable/toxic?

How about the same situation using dilute ferric chloride? Are the rising bubbles something to be scared of or is this an OK thing. I mean, I'm not planning on snuffin' the stuff up my nose or huffin' the stuff. And striking a match to it didn't seem real bright either. But I am curious about the composition of the by-products of this type of patination.

Thanks in advance for the help from the chemists among us!

Brian

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## Eric Litton

Im not a chemist, but I would say that probably anything that comes from patination is poisonous.  At the very least, I wouldnt trust any of it.

The few etching and patination projects ive done, iv done it outside and I still walked away from it everyonce in awhile to get some air.

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## Daniel Gentile

Sorry, but I dinna know lot about your question, but you've written that emerging  the piece of steel in vinegar would turn it black/blue?! what kind of vinegar you use for it?
on which steels does it work?
what temperature does your vinegar have?
how long do you let it rest?

sorry for so many questions... but since quiet a while I'm searchin' for a bloody workin' way to blue/blacken my fittings without using one of those realy poisonous and expensive gun blueing liquids....


Thanks a lot,



Daniel

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## Brian VanSpeybroeck

> _Originally posted by Daniel Gentile_ 
> *Sorry, but I dinna know lot about your question, but you've written that emerging  the piece of steel in vinegar would turn it black/blue?! what kind of vinegar you use for it?
> on which steels does it work?
> what temperature does your vinegar have?
> how long do you let it rest?
> 
> sorry for so many questions... but since quiet a while I'm searchin' for a bloody workin' way to blue/blacken my fittings without using one of those realy poisonous and expensive gun blueing liquids....
> 
> 
> ...


I was just immersing steel into plain old white vinegar and holding it for a couple of hours at 100 to 120 farenheit. It develops a cool balck/blue color but the oxide wipes right off and is not really all that attractive. It ends up a dull gray color that is *very* rust resistant. I was hoping the oxide would build up but it does not.

A better way of getting a durable black finish on steel fittings is to hold it in a damp box till it rusts like crazy and then boil the fittings in distilled water to turn the red rust to black. Then just rub the loose rust off the outside of the piece with steel wool or a cloth and pumice and then put it back in the damp box to rust again. If you do this between 3 and 10 times you end up with a very nice black finish that is very durable and rust resistant. Looks real antique like and homespun.

Or you can just polish the red rust and then oil or wax the fitting to make a nice dark red/brown finish as well.

Brian

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