Thread: Blackening Brass - Any Recipes?

It would be neat if you could get some Vantablack....99.965% absorption. So black you can't see it.

newblack.jpg

Originally Posted by Anorak Bob

Any suggestions? .

What about plating them with copper first?

Bob, i've just walked in from working all night and so my head is a bit foggy. I can't recall who's blackening solution you're using for your steel blackening. Check the MSDS however as some of them contain Selenium Dioxide, and I've read that will also blacken brass. I've never tried it but it would be worth a try if you have some there.

they can plate it black

The thread is reasonably fine, 0.75mm pitch, and the fit not loose so plating could result in non fitting parts.

There was a discussion on PM in 2004 where one member suggested a solution that utilises copper carbonate and ammonia. He says it is what Zeiss and Leitz used for blackening brass microscope components. I'm certainly no chemist so as per Pete's suggestion I had a go with some Birchwood Casey Super Blue and while the label on the container says it doesn't work on non ferrous metal, the results prove different.

A single quick immersion of about 5 seconds results in a purple brown finish. Additional dunkings remove some of that finish. ( LH end of sample ). I tried the Blackfast solution I use for steel and after about 3 minutes in the solution, the brass changed to a very faint copper colour. ( RH end ).

I might give the gun shop down the road a call to see if they carry Birchwood's Brass Black - http://westernfirearms.com.au/cleani...rs70e6tthenns2 Could be the easiest and least expensive means of achieving the finish I'm after.

Thank you all for the suggestions.

Bob.

What about black texta pen

Bob what was the verdict then on the Selenium Dioxide, not really good enough? Also how do you find it on steel? It was the latter in which I came across it, and I recall people saying it worked on brass too. Indeed it was that specific brand as it happened. For my manganese phosphating mad scientist experiments I'm doing to try dye, and I'm reasonably confident it will work, but in that case only because the surface layer is porous and I doubt that would be a solution in your case.

I'd never really thought about the need to blacken brass, but as soon as you mentioned optics I recalled quite a few things that were blackened brass that I hadn't really given much thought to. I'd be grateful if you could let us know how you get on.

Originally Posted by Anorak Bob

The thread is reasonably fine, 0.75mm pitch, and the fit not loose so plating could result in non fitting parts.

There was a discussion on PM in 2004 where one member suggested a solution that utilises copper carbonate and ammonia. He says it is what Zeiss and Leitz used for blackening brass microscope components. I'm certainly no chemist so as per Pete's suggestion I had a go with some Birchwood Casey Super Blue and while the label on the container says it doesn't work on non ferrous metal, the results prove different.

A single quick immersion of about 5 seconds results in a purple brown finish. Additional dunkings remove some of that finish. ( LH end of sample ). I tried the Blackfast solution I use for steel and after about 3 minutes in the solution, the brass changed to a very faint copper colour. ( RH end ).

I might give the gun shop down the road a call to see if they carry Birchwood's Brass Black - http://westernfirearms.com.au/cleani...rs70e6tthenns2 Could be the easiest and least expensive means of achieving the finish I'm after.

Thank you all for the suggestions.

Bob.

Hi Bob.
there is Black Oxidie for Brass but not sure if you can DIY . but in Melbourne there is a place that do this service
regards
Peter

This will darken the brass to black but may be a bit patchy for your needs

http://motherofpearl.com/darkening-solution/

Since I am babysitting the grinder all day I have plenty of time so I tried some universal black patina it has to be applied hot but came up nice and black.

Seems pretty durable

Picture to follow

photo 2.JPG

The instructions say 200 degrees C, I just waved the MAP torch over it for a bit and then brushed on the blackening.

Ray

Ray does that work on ferris metal too? Where did you buy it?

Originally Posted by Pete F

Ray does that work on ferris metal too? Where did you buy it?

http://www.barnesproducts.com.au but they are just the reseller... search for universal black patina.

The brass bits are finished ( not blackened ) - https://www.woodworkforums.com/showth...79#post1811779

There's not much to them so I don't want to overcapitalise on blackening solution. Thanks for the suggestions Peter and Pac man.

The Birchwood stuff would do the job internally and maybe externally Pete. I use the Super Blue for little things when I don't want to use the torch and oil or the Blackfast. It is not hard-wearing like the other two.

Ray's stuff looks promising.

Bob.

Hi BT,

If you like, I can send over a sample of the universal black patina for you to try?

Ray