How to Patina Brass

Last Updated: September 24, 2021 References

Patina is a natural tarnish that forms on the surface of brass and other metals. Adding a patina finish to brass pieces can give those pieces an aged look that many people find appealing. While natural patina usually occurs over an extended period of time, you can speed it up by putting the brass through a few quicker chemical processes.

Steps

Before You Begin: Clean the Brass

1
Wash all sides of the brass piece^{[1]
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Research source} Be sure to remove all of the soap before proceeding.
- Oils from your skin or other sources could coat the metal and cause it to resist the chemicals responsible for causing the patina. If the piece is not clean, the process may not be as successful as it could be.
2
Apply baking soda. Sprinkle baking soda over the surface of the brass. Scrub the coated metal thoroughly using a piece of #0000 steel wool.
- Only scrub in the same direction as the grain of the brass. Never scrub against the grain, since doing so may cause unsightly scratches.
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3
Rinse off the baking soda. Place the brass under running water to wash off all traces of the baking soda.^{[3]
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- Do not use your hands to wipe away the baking soda since doing so may distribute more oil onto the surface of the metal. Rely only on the force of running water to clean the surface this time.
4
Dry well. Use clean paper towels to thoroughly dry the clean metal.
- Again, avoid directly touching the clean metal with your hands.

Method 1

Method 1 of 3:

Ammonia^{[4]
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1
Line a deep plastic container with paper towels. Crumple up a few clean paper towels and place them inside a plastic container with a lid.
- The container should be deep enough to hold these paper towels and your brass piece, plus an additional layer of paper towel not yet added.
- A clean container that once held sour cream, cottage cheese, or another food can work well. Make sure that the container is clean and has a lid that snaps on securely.
- Never reuse this container for food afterward.
2
Soak the towels in ammonia. Pour ammonia over the paper towels in your container, adding enough to saturate the paper towels.
- Ammonia is a hazardous chemical, so you should only do this in an area that is well-ventilated. You should also protect your eyes with safety goggles and your hands with plastic or rubber gloves.
3
Sprinkle salt on top. Pour a generous amount of table salt over the paper towels in your container, distributing it evenly over the surface.
4
Place the brass inside. Rest your brass piece directly on top of the coated and soaked paper towels. Press gently so that the bottom and sides of the brass come into direct contact with the ammonia and salt.
5
Cover the brass with additional ammonia-soaked paper towels. Crumple another clean paper towel and place it directly on top of your brass piece. Pour more ammonia onto the paper towel, soaking it thoroughly.
- Use as many paper towels as necessary to cover the entire outside surface of the brass.
- You should also lift up the paper towels and sprinkle a light coat of salt on top of the brass. After doing so, cover the brass piece with your ammonia-soaked paper towels again.
6
Place the lid on the container. Secure the lid in place and set the container aside for a few hours to days.^{[5]
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- Keep the container in a safe location, away from kids and pets.
- You'll need to check on your brass piece periodically throughout the process until the desired look forms. A little patina should start forming within a few minutes, but for a more dramatic or aged look, try giving the process a day or two.
- For best results, check on the patina every 30 to 60 minutes.
- Note that your paper towels will also change color during the process.
7
Finish the brass piece. When the patina you desire has developed, remove the brass from your container and set it aside on a clean paper towel to air dry. After drying it, rinse away any remaining ammonia under running water and air dry again.
- If the patina is too dark or dense, lighten it by scrubbing the dark portions with #0000 steel wool.
- After a day or two passes, you may also want to coat the piece with clear lacquer or a soft wax to preserve the look of your patina.

Method 2

Method 2 of 3:

Oven

1
Make a solution of vinegar and salt. Combine five parts dark vinegar with one part salt, mixing well to dissolve the salt.
- You should prepare enough of the solution to completely cover your brass piece.
- Use a plastic or glass container since a metal container can have a reaction to the chemicals present, thereby tainting the process.
- Dark vinegar refers to any vinegar available in a deep shade, like black vinegar or balsamic vinegar.
2
Soak the brass in your solution. Submerge your brass piece in the salted-vinegar solution, making sure that all sides are covered. Allow it to soak for an hour or more.
- When submerging more than one piece of brass, make sure that nothing overlaps and that none of the pieces touch during this part of the process.
3
Meanwhile, preheat the oven. Preheat the oven anywhere from 400 to 450 degrees Fahrenheit (200 to 230 degrees Celsius).
- The higher the temperature, the more dramatic the patina will be.
- If desired, prepare a metal baking sheet by lining it with aluminum foil. You can leave the foil off, but leaving the pan unprotected may cause the pan to become discolored.
4
Bake the brass piece. Remove the brass from the vinegar solution and place it onto your prepared metal baking sheet. Bake it for 60 minutes, or until you like the appearance of the developing patina.
- Note that the look that develops during this time will not be the final look.
5
Reapply the vinegar solution and continue baking. Take the brass out of the oven and submerge it into the solution again for about 5 minutes, coating all sides of the piece. Return the brass to the oven and bake for another 30 minutes.
- Use tongs when handling the brass since the metal will be extremely hot.
6
Submerge the brass again. Remove the brass from the oven using tongs and dunk it into your vinegar solution again, coating all sides well.
- This final submerging will create a blue-green patina. If you do not want this tint of color, though, skip this step and move onto the next one after taking the brass out of the oven.
7
Dry and cool. Spread out two or three sheets of wax paper, layering them one on top of the other, and place the brass on top. Set it aside until dry and cool to the touch.
- This can take anywhere from a few hours to overnight.
8
Finish the brass piece. A nice patina should have developed by this point, so the brass can technically be left as is. If desired, you can buff the piece with a clean rag to enhance the appearance, or #0000 steel wool to lighten it.
- You should also consider sealing your piece in clear lacquer or soft wax to preserve the patina finish.

Method 3

Method 3 of 3:

Hard-Boiled Egg

1
Hard boil an egg. Place the egg in a small saucepan and cover it with 1 inch (2.5 cm) of cold water. Transfer the saucepan to the stove and heat the water to a boil. Immediately turn the heat off and cover the saucepan, cooking the egg in the warm water for another 12 to 15 minutes.^{[6]
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- Consider adding a pinch of salt to the water before boiling it to make the peeling process easier.
- You should turn the heat off immediately after the water begins to boil.
- Cooking the egg in this manner prevents the egg from being overcooked.
2
Stop the cooking process. Remove the egg from the hot water using a slotted spoon and rinse it thoroughly under cold running water. Keep it there until it feels cool enough to handle, but not yet ice cold.
- Chilling the egg makes it easier to handle, and chilling the egg quickly helps separate the shell from the cooked egg white.^{[7]
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  Research source} When using the egg for this process, though, you want to keep the egg a little warm, so you should avoid cooling it down too much.
3
Peel the egg.^{[8]
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Research source} Roll the egg gently on a flat surface to crack the shell. Then, use your fingers to peel away the rest of the shell.
- You'll want to preserve as much of the egg as possible, but don't worry if you lose a few chunks of egg white as you peel off the shell. The egg should still produce enough sulfur as it sits to give your brass a patina finish.
4
Cut the egg in half. Use a kitchen knife to cut the egg in half lengthwise. Note that both the egg white and egg yolk should be cut in two.
- Keep the yolk and white together instead of separating them.
- The egg yolk is an important part of this process, so it is important that you expose it in this step.
5
Place the egg and the brass in a plastic bag. Place both halves of your boiled egg into a resealable plastic bag, along with your brass piece. Seal the bag well.
- Only use a bag with an airtight seal.
- The brass does not need to directly touch the egg.
6
Set aside. Let the bag sit out at room temperature for several hours. After several hours pass, you should notice a subtle patina forming on the brass.
- The egg yolk is giving off sulfuric gas, and that gas is responsible for giving the brass a patina finish.
- Keep the egg and brass in the bag for as long as needed to achieve your desired shade of patina.
- Note that this process can get very smelly, so you may want to set the bag aside in a garage or unused room for its duration.
7
Finish the piece. Remove the brass from the bag and discard the egg. It is recommended that you seal the brass piece with clear lacquer or soft wax to protect the patina finish.

Community Q&A

Question

Which is the most effective method to patina brass?

Megan16

Community Answer

All of the methods in the article work equally well. Choose the one that is easiest for you to do.