How can one darken brass?

M ELEY · 12th June 2005, 06:01 AM

Does anyone have any idea how to turn brass to a blackened color. I remember years ago on the forum, someone talking about tannic acid. Arsenic acid is too dangerous to use. Any other formulas? Where does one acquire tannic acid? Do other acids darken brass? I have a sword with a brass repair and it would improve its look greatly.

Andrew · 12th June 2005, 06:18 AM

Hi Mark. John Lundemo recommends Birchwood Casey gun blueing. Dilute it with equal parts water. Make sure you don't get it on your skin, or leather. It'll darken very well, and you can buff it to the color you want.

tom hyle · 12th June 2005, 08:08 AM

Rubbing alcohol and gun blue, people; it's all rubbing alcohol and gun blue

No, don't mix them together (God knows what will happen, and we probably don't want to.....); clean with alcohol; darken with blueing. This tends to give brass etc. a dark brown colour, and will not always match existing patinas. Go to a student college bookstore (or maybe a library, but a college bookstore at class-starting time........online I'm sure you could find these, too), and go to the Fine Art section; there you will find metalworking books and in at least some of them tables and listings of reagents for patinating various metals in various colours; just so's you know; but, yeah; gun blue will affect many metals, and the coating it leaves is usually fairly easy to remove (BTW, in reference to a question about its affects on chrome I did some tests on chrome plated stuff I have, and if you act within a minute or so of application, the dark wipes right off; I think it hardens more over time though, especially if you leave the wetness 'til it dries down; at first when you put it on nothing will happen, but then it begins to darken; I use a paintbrush or rag, and "working it in" with a sort or rubbing/scrubby motion seems to help things along, or at least to occupy the monkey while it waits

Rich · 12th June 2005, 11:40 AM

Try Brown's Patina or Baldwin's Patina available from
Reactive Metals.

http://www.reactivemetals.com

I've dealt with them. Ask for their catalog; everything
imaginable in the way of metals and metal working
materials and patinating solutions. All items are
not on their website, so ask for a catalog or email
them about the above agents.

Rich S

M ELEY · 12th June 2005, 09:43 PM

Thank you so much,gentlemen, for your suggestions! I'll give them a try on the brass.

12th June 2005, 06:01 AM	#1
M ELEY Member Join Date: Dec 2004 Location: NC, U.S.A. Posts: 2,101	How can one darken brass? Does anyone have any idea how to turn brass to a blackened color. I remember years ago on the forum, someone talking about tannic acid. Arsenic acid is too dangerous to use. Any other formulas? Where does one acquire tannic acid? Do other acids darken brass? I have a sword with a brass repair and it would improve its look greatly.

12th June 2005, 06:18 AM	#2
Andrew Member Join Date: Nov 2004 Location: USA Posts: 1,725	Hi Mark. John Lundemo recommends Birchwood Casey gun blueing. Dilute it with equal parts water. Make sure you don't get it on your skin, or leather. It'll darken very well, and you can buff it to the color you want.

12th June 2005, 08:08 AM	#3
tom hyle Member Join Date: Dec 2004 Location: Houston, TX, USA Posts: 1,254	Rubbing alcohol and gun blue, people; it's all rubbing alcohol and gun blue No, don't mix them together (God knows what will happen, and we probably don't want to.....); clean with alcohol; darken with blueing. This tends to give brass etc. a dark brown colour, and will not always match existing patinas. Go to a student college bookstore (or maybe a library, but a college bookstore at class-starting time........online I'm sure you could find these, too), and go to the Fine Art section; there you will find metalworking books and in at least some of them tables and listings of reagents for patinating various metals in various colours; just so's you know; but, yeah; gun blue will affect many metals, and the coating it leaves is usually fairly easy to remove (BTW, in reference to a question about its affects on chrome I did some tests on chrome plated stuff I have, and if you act within a minute or so of application, the dark wipes right off; I think it hardens more over time though, especially if you leave the wetness 'til it dries down; at first when you put it on nothing will happen, but then it begins to darken; I use a paintbrush or rag, and "working it in" with a sort or rubbing/scrubby motion seems to help things along, or at least to occupy the monkey while it waits

12th June 2005, 11:40 AM	#4
Rich Member Join Date: Dec 2004 Location: comfortably at home, USA Posts: 432	Try Brown's Patina or Baldwin's Patina available from Reactive Metals. http://www.reactivemetals.com I've dealt with them. Ask for their catalog; everything imaginable in the way of metals and metal working materials and patinating solutions. All items are not on their website, so ask for a catalog or email them about the above agents. Rich S

12th June 2005, 09:43 PM	#5
M ELEY Member Join Date: Dec 2004 Location: NC, U.S.A. Posts: 2,101	Thank you so much,gentlemen, for your suggestions! I'll give them a try on the brass.