Colouring brass, bronze and copper formulae

[Tarbicus]

http://www.coscosci.com/patinas/patinaformulas.htm

Patina Formulas for Brass, Bronze and Copper

Gives the formulae and methods for changing the colour of brass, bronze and copper. So if you feel your brass is too pale and bright, could come in useful.

Example:

16. Golden Yellow
Ingredients

* Sodium Thiosulfate... 1/4 oz
* Ferric Nitrate... 2 oz Buy Ferric Nitrate
* Distilled Water 1 quart

Process

Heat solution to a boil. Dip.

Disclaimer from the Science Company:
The Science Company has collected these recipes from a variety of sources through the years. The formulas have not been personally tested so there is no guarantee that they will work. We suggest they be employed on a "trial and error" basis first so their effectiveness can be judged by the user.

[Robert Vermaat]

Nice link, thanks.

Disclaimer from the Science Company:
The Science Company has collected these recipes from a variety of sources through the years. The formulas have not been personally tested so there is no guarantee that they will work. We suggest they be employed on a "trial and error" basis first so their effectiveness can be judged by the user.

OOPS!! hock:

[Tarbicus]

OOPS!! Shocked

Oh just try it on a piece of waste brass I'm looking for a supplier of ferric nitrate in the UK. Also need to get around the issue of how to do it to something that's already attached to lots of other bits.

[Tarbicus]

Just stumbled across this:

For anyone who's ever been in the military and had to frequently polish brass, one of the things that produce the quickest and very nice colored "patina" is the human fingerprint. Just one touch on a piece of shiny brass or copper will start showing a nice color in a matter of hours - LOL. So, using that concept, I came up with something that combines the principle elements of a fingerprint: water, salt, oil, acids, mild caustics, and amino acids.

If you're interested, here's Fred Flintstone's recipe for the mixture I've used with very good success - for about 1.5 gallons of mixture:

1. One gallon of water
2. One cup of filtered bacon grease thinned with about 1/2 cup cooking oil (amino acids and oils).
3. Two cups of sea salt (aquarium salt from Wal-Mart or pet store).
NOTE: Sea salt works much better than table salt because it contains many other reactive elements that enhance the oxidation process.
4. One quart of white vinegar (mild acid).
5. Liquid dishwashing soap (mild caustic and wetting agent).

Mix the water and vinegar (acid) together; then begin stirring in the sea salt. Keep adding salt in small quantities (amounts will vary with water quality) and stir it in well to make sure it all dissolves. Add more salt and stir it in well again. Stop adding salt when the water becomes completely saturated and a little undissolved salt starts falling to the bottom of the container when you quit stirring for a few seconds. The bacon grease (amino acids and oil) should be thinned with only enough cooking oil so that it is not solidified at room temperature. Without stirring the mixture, simply
pour the bacon grease/cooking oil mixture into the solution (yes, I know it won't mix). Now, begin adding liquid dishwashing soap just a little bit at a time as you gently stir it into the mixture; continue adding a few drops of soap at a time (while stirring) until the layer of oil "mixes" with the solution. The object here is not to create a sudsy mess, but only to add enough dishwashing liquid (as a wetting agent) until the oil becomes part of the solution instead of floating on top. Brent

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