How to Make Patina
A patina is typically an organic finish that occurs on the surface of metal or wood after a period of aging. Wood surfaces develop a sheen and a change in color while metallic surfaces become tarnished through oxidation and other naturally occurring chemical reactions. If you wish to create a patina finish on a newer or clean metal, that can be achieved by mixing a chemical formula and applying it to the surface of the metal. Read on to learn how to make a generic patina mixture as well as three specific formulas.
Mix the chemical compound with the distilled water. Most chemicals used to make a patina finish are water soluble and can be mixed in any sort of container. Use an old pot if you need to heat the solution, otherwise check the label on chemical container to ensure you are safely mixing your chemicals.
Clean the surface of the metal to which you are applying the patina with rubbing alcohol or any cleaner that will remove the oil left by your hands. Wear rubber gloves while washing the metal and clean with a rag or a scrubbing pad.
Apply a patina primer with a brush or primer. This step is only necessary for some colors and types of metals so check the instructions for the chemical compound you are using. The primer is similar to the finish patina, but prepares the metal to be finished instead of providing a finish.
Apply the patina to the metal. Application methods vary depending on the metal and the type of compound you are using. Some patinas are better when applied with a spray bottle and others are better when applied with a brush. Check the instruction for the type of patina you are using. Also, some patinas need the metal to be heated to accept the patina properly, while others can be applied to the metal at room temperature. Apply as many coats as necessary.
Seal the patina with a wax. Some patinas continue to change color or are prone to peeling if they are not sealed. Wax is applied with a clean rag. Dip the rag into a container of wax and lightly coat the metal.
Mix 1/3 ounce of ammonium chloride and 3 ounces of cupric sulfate with a quart of distilled water in a metal pot. Both compounds are water-soluble and will dissolve in the water.
Heat the solution to between 180 and 190 degrees Fahrenheit.
Heat the metal to approximately 200 degrees Fahrenheit with a torch or other heat source you may have available.
Apply the hot chemical solution with a brush while the metal is still hot.
Allow the metal time to dry and to cool to 100 degrees Fahrenheit, then wash under cold water. Repeat these steps until you reach the desired tint.
Brown Patina for Cast Bronze
Mix 80 grams of cupric nitrate and 100 milliliters of nitric acid, 10 percent, with 1 liter of distilled water in a heat-proof container.
Heat the solution until it reaches a temperature between 140 and 158 degrees Fahrenheit.
Immerse the metal into the heated solution with tongs.
Remove the metal after five minutes and rinse with warm water.
Let the metal dry and repeat the process as necessary. When satisfied seal the metal with a coat of wax.
Red Patina for Copper
Mix 25 grams of cupric sulfate with 1 liter of distilled water.
Bring the solution to a boil and immerse the copper into the solution for 15 minutes.
Remove the copper from the solution and rinse with hot water. While the copper is being rinsed, add a half a gram of ammonium chloride to the cupric sulfate solution and continue to boil the solution.
Immerse the copper into the new solution for 10 minutes.
Remove the copper and rinse with hot water. Once the metal dries finish it with wax, if desired, or leave as is.
Things You Will Need
- Distilled water
- Chemical compound
- Heat source
- Rubber gloves
- Spray bottle
- Cleaning solution (rubbing alcohol)
- Scouring pad
- Ammonium chloride
- Cupric sulfate
- Cupric nitrate
- Nitric acid, 10%