Blackening copper/brass?

CLANG · Post by **CLANG** » Tue Feb 17, 2009 4:29 am

Do any of you folks have a product that you like for the process, or a home-brewed concoction? I'm aware of several commercial chemicals, but I haven't actually used any of them. What I'm looking to get (ideally) is a deep blue-black. Any suggestions?

lorenzo2 · Post by **lorenzo2** » Tue Feb 17, 2009 10:08 am

Liver of sulfur works very well for copper but produces a black with undertones of grey, not blue. It does not work well on brass due to the zinc content. On brass it produces a light grey.

CLANG · Post by **CLANG** » Thu Feb 19, 2009 6:34 pm

*bump*

Checking a handy reference, I see that's potassium sulfide.

Any other suggestions?

Mad Matt · Post by **Mad Matt** » Thu Feb 19, 2009 7:29 pm

gun blue works on brass. You can clean it off with brasso though so it's probably not very durable.

audax · Post by **audax** » Thu Feb 19, 2009 8:52 pm

Birchwood-Casey makes a product specifically for blackening brass.

I used to use some stuff in the military to blacken brass for my subdued insignia. Can't remember what it's called anymore. Got it at the PX.

Cassius the Rabbit · Post by **Cassius the Rabbit** » Fri Feb 20, 2009 12:50 am

I use Brass copper bronze oxidizer #1 331-022 from Rio Grande
it says on the bottle contains Selenious acid whatever that is

Milan H · Post by **Milan H** » Fri Feb 20, 2009 11:29 am

http://www.jaxchemical.com/jaxshop/shopexd.asp?id=61

I have heard some good about this companies products. I dont know how they work myself, but may be worth a shot.

Cheers!

Medieval Miscreant · Post by **Medieval Miscreant** » Fri Feb 20, 2009 4:58 pm

PAINT!

Sorry, I couldn't help myself.

Adric13 · Post by **Adric13** » Fri Feb 20, 2009 6:41 pm

bleach gave me a black on copper.
so did hydrogen peroxide.
peeing on it turned it green.
heat, pee, salt and vinigar gave different, browns, greens, blues and blacks. Unfortunately many of the colours were lost when i sealed it. This is the counter top i made for my kitchen bar area. there was blues in it but they went away.... :sad:

oops file too big no way to make smaller on this 'puter...

Derian le Breton · Post by **Derian le Breton** » Sat Feb 21, 2009 12:17 am

Ammonia gives a nice green too (on copper at least.)

-Donasian.

CLANG · Post by **CLANG** » Sat Feb 21, 2009 9:56 pm

Hey, Adric-do you just randomly pee on stuff to see what color it will turn? :lol:

I remember hearing that the workers who were re-furbing the statue of liberty would just take a leak off the scaffolding onto the side of the statue to help the new parts... integrate. Made a media stink IIRC.

I've had the "loss of color" problem with the copper roses that I heat-color if I try to seal them in any way. Wax, lacquer, oil, even silicone spray all erase most of the cool colors. I just leave them un-protected and advise folks not to handle the copper part excessively.

Thanks for the suggestions. Most of them are jiving up with stuff I'm gleaning from ye olde internet. I've found a number of useful tips. One of the most universal seems to be to use a dilute solution of the reagent, like 1:2 or even 1:10, instead of using it directly from the bottle. Takes longer, but makes a much better finish, according to reports.

I'm pretty sure selenious acid is the same main ingredient in Kleenbore's Black Magic gun bluing solution.

Adric13 · Post by **Adric13** » Sat Feb 21, 2009 11:24 pm

CLANG wrote:Hey, Adric-do you just randomly pee on stuff to see what color it will turn? I remember hearing that the workers who were re-furbing the statue of liberty would just take a leak off the scaffolding onto the side of the statue to help the new parts... integrate. Made a media stink IIRC.

I've had the "loss of color" problem with the copper roses that I heat-color if I try to seal them in any way. Wax, lacquer, oil, even silicone spray all erase most of the cool colors. I just leave them un-protected and advise folks not to handle the copper part excessively.

Thanks for the suggestions. Most of them are jiving up with stuff I'm gleaning from ye olde internet. I've found a number of useful tips. One of the most universal seems to be to use a dilute solution of the reagent, like 1:2 or even 1:10, instead of using it directly from the bottle. Takes longer, but makes a much better finish, according to reports.

I'm pretty sure selenious acid is the same main ingredient in Kleenbore's Black Magic gun bluing solution.

ummm yea..... mabey..... ok so i peed on it!

actually being a home inspector i see LOTS of bath rooms. the cooper pipe behind the toilet is usually green. thats either do to cleaning solution (not likely) or pee (much higher degree of likely in the kids bath anyway) so i tried it. worked bout as well as any of the other stuff i had tried. the real story is how i figured out girl pee is stronger than boy pee.....

don · Post by **don** » Sun Feb 22, 2009 2:09 am

Adric, would a "buddy" named Jose be involved in finding out?

Clang, if you have a jewellers supply close by, you should be able to find liver of sulfur. If you look in Micheals, they may have something

bkillian · Post by **bkillian** » Sun Feb 22, 2009 3:15 am

M-nu is the military stuff