4 Killer Methods to Darken Copper Sink

Copper’s natural color is a warm reddish-brown tone that comes from the mixture with alloys such as bronze and brass. If you’re looking for solution to darken copper sink, you’ll get various methods to solve the problem.

We will show you a step-by-step guide that instructs you on how to darken copper sink quickly and naturally, using liver of sulfur, along with green and brown patina. You will also see common questions and warnings you must keep in mind.

This beautiful metal is used in various applications including electricity, plumbing, pharmaceutical, and construction. A copper sink is a stunning addition to any space, however, it does require maintenance to bring out its natural beauty.

Once you become familiar with the color-changing process of copper, you will feel confident owning this metal for years to come. You will learn what to expect from a copper sink as it discolors with oxidation over time and how to tarnish it to keep it looking its best.

How to Darken Copper Sink Naturally:

Copper changes color over time uniquely to each home and location. The distinct shade that copper forms is called patina and it is a result of copper’s reaction with oxygen that creates copper oxide. Learning about how the patina on copper forms helps you understand the unique ways you can create different finishes naturally.

Step 1: Clean Copper Thoroughly

First, protect your hands with gloves to avoid chemical reactions on your skin. Then, start by cleaning your copper sink very well, ensuring there are no traces of oil or dirt. Use a soft sponge, warm water, and your regular dish soap.

Step 2: Rinse, Sprinkle, and Scrub

Once you wash the sink with soap and wash away all the suds, you will take baking soda and sprinkle it all over the surface. Using steel wool, begin to gently scrub the surface of the sink. This will remove all excess particles or coating that could be stuck on the surface.

A good scrub will expose the layer of copper to the oxidizing agent that will darken it. Now, it is time to rinse off the baking soda very well. You may use your gloves to rub the surface, ensuring that all baking soda particles are off.

Step 3: Apply Solution and Dry

Make a solution that contains three parts water, vinegar, and salt. Mix well until all the salt crystals dissolve. Let the solution penetrate the copper sink surface for at least 30 minutes. You are looking to let the copper soak in the solution.

When it finishes soaking, do not wipe it clean, instead, let it air dry until all the solution is absorbed. You may use salt to sprinkle all over and speed up oxidation.

Darkening Copper Sink With Liver of Sulfur

Another great method for darkening copper is using liver of sulfur, which looks and smells bad, but works like magic! It is a chemical compound that creates an antique-looking patina on copper and other metals. When looking for solution to darken copper sink, you can buy this product in gel, liquid, or lump form.

Step 1: Clean Sink

Start by cleaning the sink thoroughly using dish soap or a grease-cutting cleaning solution. This gets rid of any build-up or debris that may be stuck on the surface. Be sure to use gloves and avoid touching the sink. Your fingerprints may contaminate the surface that will cause the metal to resist the patina.

Step 2: Oxidize Surface with Liver of Sulfur

Once the surface is clean, you are ready to apply the liver of sulfur to start the oxidation process. If you have to mix the solution, follow the instructions according to the label. The easiest way to use liver of sulfur is to buy pre-mixed solutions such as liquid forms.

Be sure to ventilate the area well as fumes can be harmful. Liver of sulfur can turn copper dark very quickly and deeply. Start with a small and brief application to experiment with the finish you desire as it can turn copper black.

Step 3: Rinse With Baking Soda Bath

Prepare a solution of baking soda and water in advance to stop the darkening process when you have achieved the shade you desire.

Since you are working with a sink, you will need to prepare enough solution to cover the whole surface. Work with a rag since you won’t be able to soak the whole sink in the solution.

Step 4: Dry and Polish

Using a lint-free cloth, wipe the surface of the sink until dry. For a shiny look, you may use polishing paper or pads. To maintain its shine, you can buff it regularly with a polishing cloth.

Darkening Copper Sink With Green Patina

The natural shade of a bluish-green patina gives copper a unique character. A famous monument that features a green patina is the Statute of Liberty.

Step 1: Clean Copper

Wash the sink using a lint-free rag and dish soap. Be sure anything stuck on the surface is washed off.

Step 2: Mix Solution

Mix the darkening solution with two parts white vinegar, half part non-iodized salt, and one and a half parts of clear and detergent-free ammonia.

Step 3: Spray Solution

Pour the solution into a corrosion-resistant plastic spray bottle and evenly spray the surface. Be generous ensuring you cover thoroughly every corner of the sink.

Spray quickly using a fine spray because large drops can cause streaks. A little goes a long way, try to be conservative as you can always add more later.

Step 4: Set For One Hour

Once the sink is soaking in the solution, allow it to sit for one hour. The solution needs to be left undisturbed.

Step 5: Repeat application

After the first application, you will notice areas that you might have missed. Reapply the solution being extra generous around those spots. It is a matter of experimenting with the process and finding out how you can achieve the shade you are looking for.

Step 6: Allow to Dry

The patina will dry to a green powdery finish. Avoid rubbing the powder and allow it to sit overnight. The green finish will set permanently over time. You may be tempted to rub off any excess green powder, but it can ruin the finish. It is best to let it sit for at least six hours.

Darkening Copper Sink with Brown Patina

To darken a shiny copper sink that resembles a penny, brown patina is the way to go. It is a simple way to give your copper piece a classic finish.

Step 1: Clean Surface

Begin the process by cleaning a copper farmhouse sink with a lint-free rag, water, and dish soap, or other grease-cutting solution. This step is important to have a working surface that is free from any type of build-up that can interfere with the finish.

Step 2: Make Baking Soda Darkening Solution

Simply add baking soda to hot water until it is completely dissolved. Place in a spray bottle that provides fine mist and avoids drops that can cause streaks.

Step 3: Spray Solution on Sink

Using an even coat, spray the sink thoroughly making sure you don’t miss any areas. To cover hard-to-reach corners, you may use cotton swabs soaked in the solution.

Step 4: Allow to Dry

After you completely soak every inch of the sink, allow the solution to air dry. Do not wipe at this point or it can alter the finish. After the surface is completely dry, you will want to let it sit for at least one hour.

After allowing it to sit for one hour or longer, you can revisit the surface with the solution, using the same method as in the previous step. You will want to do a second coating of the solution only if you are trying to achieve a darker color.

The finish will not be powdery like the green patina, instead, it will have a clean surface. Having a penny you can compare the sink to during the process will help you determine how dark you want to make the copper.


  • Always wear protective gear including gloves, goggles, masks, and clothing. These products can cause adverse reactions if in touch with skin, eyes, or inhaled.
  • Put together a first aid kit in case of an accident. Know what to do if any part of your body comes in contact with the solution. Remember that you must protect your respiratory system as well.
  • Materials used for copper sink patina repair are considered hazardous waste and must be disposed of correctly. You cannot simply throw the items away in the trash.
  • When using liver of sulfur in lump form, beware that it is poisonous if inhaled and can also be a fire hazard as it is flammable.


How Can I Darken Copper Quickly?

Since natural weathering takes years for copper, chemical solutions are necessary to speed up the darkening process. Conversion coatings, acid sulfate solutions, and other chemicals are used.

Does Vinegar Harm Copper?

Vinegar generally removes oxidation from copper. Generally, it does not harm copper, but only when used in specific mixtures. On its own for extended periods will not have the same reaction as when mixed in a solution for a brief soak.

The vinegar reacts on the metal to effectively dissolves copper oxide, making the surface shiny again, like a brand new penny.

What is Patina on Copper?

Patina refers to the thin layer that variously forms on the surface of copper and other metals. It is a tarnish created by oxidation and often appears as a powdery bluish or greenish coating.

Can I Use Vinegar to Clean Copper?

Yes, however, the vinegar must be part of a solution and used appropriately. You can use a soft cloth to rub the copper with a mixture of water, vinegar, and salt. Rinse off until the solution is completely off and dry thoroughly.


As you can see, copper is a “living” metal that changes over time. It reacts to its environment and specific chemicals applications. Knowing how to achieve the tone of copper you are looking for becomes a fun hobby.

The more you know about copper, the more likely you will have a sink that resembles what you envision. A copper sink creates a charming addition to any place. It does require careful attention to maintain its best appearance.

Simple ingredients and processes make it easy to do the copper darkening yourself. You must take necessary precautions to protect yourself and your family from toxic chemical reactions.

No matter what shade of copper you dream of, there are recipes for you to try to help achieve the precise look you’re going after. As you learn how to darken copper quickly, it is a good idea to practice on other copper items you don’t mind experimenting with. It is a fun experience that will keep your copper sink looking the very best!

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