Date Uploaded: March 14, 2003, 11:30 pm
Last Edited: August 7, 2012, 9:52 pm
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Bluing Copper with Ammonia
Article © MAIL User: Drax
Target metals: Copper, Brass, Bronze
Target colors: Blue, dark
This solution will turn copper containing alloys into a blue color. This recipe comes from The Complete Metalsmith, by Tim McCreight. Be careful of the ammonia!!
There's no real solution to mix up, but you will need the following:
Method of use: First, sprinkle the pieces you want to blue with the salt. It may help to wet the surface first with water. Then place some ammonia in a dish or a bowl and put your piece on a separate dish. Enclose both the piece and ammonia in the same space (by using an overturned larger bowl, or whatever works) and let sit until the piece turns the color of blue you want.
I found that adding a lot of salt on the piece also with a lot of water helped speed up the process, but don't suffocate the piece with salt.
The brass I used turned an incredibly dark blue! The bronze was a little lighter, but still a dark blue. Once piece that I added later turned sky-blue/green, but I'm not sure why (it's possible the ammonia concentration was less then).
The color is very stable, but can still be scratched off by using pliers (but it does not flake off). This color would probably be very stable to hitting other pieces, such as in a mesh of chainmaille. Very nice color!!
The picture shows a bronze ring on the left and its colored version below. The brass is on the left with its colored version, and the lighter-blue ring mentioned in the text at the bottom.
Original URL: http://www.mailleartisans.org/articles/articledisplay.php?key=132