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How to age copper

How to age copper

Aged copper, whether a classic blue-green or a deep cinnamon tone, is simply stunning, yet it can take years to achieve a truly aged look naturally. This finish is the result of a patina developing over the copper, a protective film that keeps the copper below from corroding further. You can create similar effects with store-bought patinas, a solution commonly used in photography development or more common household materials. Start by cleaning the copper thoroughly with kitchen spray and a scrub brush, rinsing it clean with water and drying it with a lint-free cloth.

Blue-Green Look

Add blue-green copper patina solution to a plastic dish. Apply the solution to the copper with a foam brush, leaving some of the copper untouched for a slightly distressed look. Let this dry completely, watching the color change.

Apply a second coat of patina if the initial color is not to your liking. Keep repeating this process, applying the patina and then letting it dry, until the copper is a color you like. If the shade becomes too opaque, go back in with a scrub brush or sandpaper to scuff the finish.

Spray the copper with a clear topcoat intended for metal. This prevents further oxidation, maintaining the current look.

Darkened Look

Sand the copper with fine-grit sandpaper and then with ultra-fine grit sandpaper. Wipe away the dust with a clean, damp cloth and wipe the piece dry with a lint-free rag.

Combine 1 part photography rapid fixer with 2 parts clean water in a shallow glass or plastic dish. The dish needs to be large enough so that the copper can lie flat in it and deep enough so that the piece is fully submerged. To keep a lighter effect on the face of the copper, only add enough diluted rapid fixer to come up just along the edge of the piece.

Cover a work surface with a drop cloth and place the copper inside of the dish. Let this sit for 10 minutes or more. If you opted to keep the solution shallow, rock the dish back and forth and side to side, sliding it across the work surface, allowing the solution to wash over the face of the piece while keeping the bottom portion submerged. Watch the copper as it slowly changes color, stopping when it reaches a finish you like.

Rinse the copper with clean water and let it air-dry. Repeat this process again if you want the copper darker. Once you have a finish you like, apply a clear spray sealant meant for metal to complete the look.

Colorful Looks

Add about a thumbnail size amount of liver of sulfur and a drop of ammonia to 1 cup of warm water. Dip the copper in the solution and then buff it away with a clean cloth. Rinse thoroughly and allow the piece to air-dry. This creates a rainbow effect of blues and pinks on the metal.

Place the copper in a resealable bag with a warm, halved hard-boiled egg. Close the bag and let this sit for three to four days, or until the copper is a shade you like. This creates a blackened effect on the metal.

Rinse the copper in mineral water and let it air-dry. This creates a natural variation in the color, perfect for a more subtle look.

Apply a clear sealant after each of these methods to protect the new patina.

How to age copper

While working on a recent commission I encountered the challenge of making shiny new copper look old and weathered. While I thought I remembered from my elementary school days some simple concoction of vinegar, upon further research it seems the simple recipe I remember is for making OLD copper look new and shiny – wrong way. After online research galore, several trips to the hardware store, and some trial and error, here is the recipe I came up with:

For prepping the surface you will need:

How to age copper

Rubber gloves

Acetone (nail polish remover might work) for removing any varnish

Windex original formula

Steel wool and/or scotch pads for roughing up surface

For the aging solution you will need equal parts:

How to age copper

**Spray bottle to mix them in, if desired

How to age copper

How to age copper

How to age copper

**In my experience sprinkling some salt crystals directly on the surface after applying the solution will give some interesting pitting effects if you’re going for that.

I repeated this process twice, leaving the copper in the bag for 1-3 hours each time. After gently washing away the loose bits of patina using water and a scotch pad my results were thus:

How to age copper

To see Sara’s Steampunk Journal completed with front and back copper covers, click HERE.

Do any of you have tips for aging copper or brass manageable from an apartment patio? Please share in the comments!

What Others Are Saying

My opinion is you sloughed off too much of that gorgeous color. You MANAGE the patina of copper and it took practice for me to achieve the look I wanted.
Also, shine is a SIN on this finish. When I carved and painted waterfowl, we called it ‘that sheen’. It’s allusive, but the ah-ha moment.

How to age copper

Copper tarnish occurs in a multi-stage process that first gives the metal a deep red color, then a black hue and finally the sea-green patina made famous by the Statue of Liberty and world landmarks such as the Berlin Cathedral, Vienna’s Belvedere Palace and the Parliament Building in Victoria, British Columbia. Copper tarnish may be a feature on architectural structures, but it can be an eyesore on copper sinks and pots, and there are ways to remove it.

However, when you remove the patina, you expose the copper to further tarnishing. Although it may be unsightly to some, the copper patina protects the metal underneath, which is why copper lasts so long outdoors.

Copper Tarnish Isn’t Rust

Copper tarnish, like rust, is caused by oxidation, but they aren’t the same thing. Rust occurs in metals that contain iron, and the end result of oxidation is iron oxide, which is a flaky compound that falls away, exposing more of the metal to oxidation and degrading it.

None of the compounds produced by copper oxidation are as fragile. They remain on the surface, and while intermediate compounds continue to oxidize to produce the final patina, they protect the metal underneath. Copper corrosion can lead to deterioration, as occurs with copper water pipes, but that’s usually because of an exacerbating factor, such as water with high very high or low pH or high levels of dissolved salts or oxygen.

The Stages of Copper Corrosion

In the first stage of the formation of a patina, copper reacts with oxygen in the air to form copper (I) oxide:

This turns the copper a reddish color. In the second stage, this compound reacts with oxygen to form copper(II) oxide (CuO), which is black:

You can observe these reactions for yourself by placing a sheet of copper on a gas stove burner. It first turns red, then black.

The final stage of patination occurs more slowly and usually takes several years. Copper (II) oxide and copper (II) sulfide (CuS), which is another black compound that forms when there is sulfur in the air, react with carbon dioxide (CO2) and hydroxide ions (OH – ) from water in the air to form three compounds:

  • Cu2CO3(OH)2
  • Cu3(CO3)2(OH)2
  • Cu4SO4(OH)6

These are the compounds that form the patina.

A copper patina develops faster in polluted air that contains a lot of sulfur, which is a byproduct of burning fossil fuels.

How to Clean Copper Tarnish

A copper patina is desirable on a historic building, and some people like the look of tarnished copper sinks and pots, but others prefer the look of new copper. If you’re one of these, you need a weak acid that will dissolve the copper compounds without harming the metal. You don’t need to look any farther than your kitchen cupboards for a good copper cleaner that isn’t toxic, as some commercial copper cleaners are.

Virtually every website that offers advice on cleaning copper recommends vinegar and salt. Sprinkle salt on the metal and rub with a cloth soaked with vinegar and let the reaction between sodium chloride and acetic acid do the work. For hard-to-remove tarnish, fill your copper pot with salt water, add vinegar and bring to a boil.

To prevent tarnish, you need to coat the copper with a film that prevents exposure to the atmosphere. Both copper polish and lacquer are effective for sinks and decorative items, but neither should be used on cooking implements.

How to age copper

Copper almost seems to be a metal made for woodworkers. Its warm, rich color complements wood rather than fighting with it for our attention. And, copper, one of the first metals used by man, works easily.

These virtues gave copper widespread popularity during the Arts and Crafts movement early in this century. Arts and Crafts homes and furnishings, which stressed the beauty of natural materials and handwork, often combined copper and wood.

So, when we researched a clock project, we decided that the shiny, new copper on the face needed an aged look, as shown above. After some experimenting, we came up with a simple way to give copper that been-around-awhile look for projects in the Arts and Crafts style.

Working with copper Many crafts-supply stores sell copper sheets for handcrafting, or you can buy it from a metals dealer. Copper comes in scores of alloys, though, so tell the dealer you want a soft, malleable one that you can work by hand.

Mark your cutting lines on copper with a scratch awl or other scriber. Pencil marks don’t show up well on metal, and markers usually make lines too wide for accurate work.

Use a straightedge with nonskid backing. (If you don’t have one, put a strip of double-faced tape on the back of a ruler. Press it against your shirt sleeve a couple of times to reduce the tape’s tack before starting the layout.) Scribe curved lines against a French curve or template, similarly skid-proofed. For complex layouts, adhere the pattern directly to the metal with spray adhesive.

Copper cuts easily. Common tin snips will readily handle straight cuts and gentle curves in sheet copper about 1 ⁄32 ” thick or less. As you cut, don’t close the snips all the way. Doing so crimps the metal’s edge every time the jaw tips come together. Instead, keep the snips moving forward so the cutting takes place mostly at the back of the jaws.

You also can cut this soft, non-ferrous metal with a scrollsaw, bandsaw, or portable jigsaw. Back the metal with scrapwood at least 1 ⁄4 ” thick for power sawing.

A no. 5 blade (.038x.015″ with 16 teeth per inch) works fine for a few quick scrollsaw cuts. For serious copper sawing, go with a metal-piercing blade (24-48 teeth per inch), and lubricate it with beeswax. If you have a variable-speed saw, run it at a slow speed for metal cutting.

For the bandsaw or jigsaw, select a general-purpose or metal-cutting blade with 14 or more teeth per inch. If you’re using the jigsaw, clamp the workpiece securely to the workbench, the cutting line overhanging the edge. Cover the saw’s baseplate with masking tape to prevent scratching the copper.

Smooth and true cut edges by filing. For best results, clamp the metal between two pieces of scrapwood in a vise. Stand the metal’s edge about 1 ⁄16above the wood, as shown, and draw a mill-cut bastard file along the edge.

How to age copper

Lay out and drill any required holes before finishing the metal. This way, you won’t risk marring the finished surface.

Giving copper the old look

Over the years craftsmen have used various treatments to give new copper an old look. One old method, still employed by some artisans today, involves bathing the copper in a solution made by dissolving chunks of liver of sulfur (potassium sulfide) in water. But this process poses a hazard. “Potassium sulfide hydrolyzes in water, releasing hydrogen sulfide (H2S), a gas as toxic as the hydrogen cyanide used in a gas chamber,” warns Dr. Jim Lindberg, professor of chemistry at Drake University. “Without adequate ventilation, it will kill you,” the chemist says.

The thought that aging copper this way might suddenly stop our own aging led us to try some other methods. In tests, we achieved best results with another chemical — rapid fixer, a common photographic material. Camera shops usually sell rapid fixer, or you can check the Yellow Pages for photographic-supply retailers. (We bought a 16-ounce bottle of Ilford Universal Rapid Fixer. Kodak and others market a similar product.)

Cleaning the copper is the first order of business. To remove oils and dirt, scrub both sides with kitchen cleanser. Rinse well.

Then, sand the exposed face to a satin sheen, using a fine (red) Scotchbrite pad followed by an ultrafine (gray) one. Don’t make fingerprints on the copper — wear gloves or hold the piece with clean rags. (We wore latex medical gloves throughout the operation and handled the copper by the edges.) Wash off the sanding residue. (We swabbed it off with denatured alcohol.)

Dilute the rapid fixer 1:2 with water. To do this, pour a measured amount of fixer into a clean two-liter pop bottle (or similar suitable container), and then add twice that amount of water. Stir or shake to mix.

Pour about 1″ of dilute fixer into a suitable glass or plastic tray. (We bought a plastic photo-developing tray at the camera store where we bought the rapid fixer.) Slip the copper face-up into the chemical. Rock the tray gently to keep the solution moving across the copper’s surface, as shown.

How to age copper

After a few minutes, the surface will begin to darken. Continue agitating until the copper takes on roughly the color of cinnamon. (Reaching this final shade can take 10 minutes or so.) Don’t let the color get too dark — that hides the copper look.

Rinse both sides under running water, and then stand the piece on edge to air dry. You can help it along with a hair dryer or heat gun, but don’t rub the surface. After the copper dries, check the color. If you’ve hit one you like, spray on clear gloss lacquer or acrylic coating.

You can reimmerse the metal to darken it. To lighten it, though, you’ll have to sand to bright metal and start over again.

Give your decorative metals, be they silver, copper, or cast iron, a delightfully distressed makeover with these easy DIY techniques.

How to age copper

Today, many homeowners strive to achieve a lived-in vibe with their interior design choices. Who wants furniture that looks like it just came out of a catalog? Or a pallet project that trumpets the fact that it was made just last weekend? Those same DIYers who go to great lengths to distress wood so their furnishings radiate vintage appeal also don’t want brand-new metal accents that stick out like a sore thumb. The solution? Age the metal to conceal the recent genesis of your furniture while creating a striking decorative finish. Unlike such materials as glass or tile, metal may even look better with a little antique patina than it does in its unblemished state—so much so that you might want to age all your metal accents. Fortunately for DIYers, the prospect of aging metal yourself doesn’t have to give you gray hairs. Read on to learn how to take the shine away from silver, copper, and cast iron with a minimum of steps and materials.

To help you figure out the best way to age metal, we outlined the following three methods:

  1. Place silver in a freezer bag with the yolk of a hard-boiled egg to achieve a rich patina.
  2. Soak copper in a solution of water and rapid fixer to age the metal. Or, for a blue-green patina, soak it in a mixture of water, vinegar, and salt.
  3. Lightly ding cast iron with a hammer, or run sandpaper across the surface.

How to age copper

Method #1: When Sulfur Met Silver

NOTE: This technique works best on sterling silver of 92.5% purity or lower.

STEP 1

Before aging silver, hand-wash it with soap and cold water to remove surface oils. Put on a clean pair of gloves before handling the washed silver to prevent the oil on your fingers from transferring to the piece.

STEP 2

Bring a pot of water to a boil, toss in one egg (or two, for larger silver pieces), and cook until the egg is hard boiled. Remove the egg from the pot and crack it open, separating the yolk from the white.

STEP 3

Place the silver into a freezer bag with the crumbled yolk of the hard-boiled egg, but don’t let the yolk touch the silver. (If they touch, you may end up with spotting in your new patina.) For larger pieces of silver, you may need to use a paper towel to separate the metal from the yolk. Seal the bag, and let it sit for six to eight hours. The silver will soon begin the aging process, thanks to the sulfur in the eggs.

STEP 4

It’s time to unleash the power of science! Open the bag outdoors so the sulfur fumes don’t invade your home. Remove and clean the aged silver with soap and water, gently buffing the high points with a clean cloth to reveal a rich patina.

How to age copper

Method #2: Photo-Finish Copper

MATERIALS AND TOOLS Available on Amazon
– Soap
– Water
– Steel wool
– Shallow plastic tray
– Rapid fixer (found in camera stores)
– Vinegar (optional)
– Salt (optional)
– Gloves
– Soft-bristle brush
– Copper sealant spray

STEP 1

Clean the copper with soap and water to remove surface residue, then scrub it with steel wool.

STEP 2

Fill a shallow plastic tray with a solution of two tablespoons water and a tablespoon rapid fixer—a fluid used for photographic processing. If you prefer copper with a blue-green complexion, swap the rapid fixer for a solution of equal parts vinegar and salt.

STEP 3

Put on gloves, and submerge the clean copper in the solution for up to 10 minutes. You can also use a brush to coat the surface of the copper.

STEP 4

Remove the copper from the bowl and let it air-dry completely to reveal either a dark patina or a timeworn turquoise tint, depending on the ingredients you selected in Step 2.

STEP 5

Rinse the copper in cool water. Allow the piece to dry fully before coating it with a fast-drying copper sealant spray, which will maintain its beauty for years to come.

How to age copper

Method #3: Make an Impression on Cast Iron

MATERIALS AND TOOLS Available on Amazon
– Hammer
– Sandpaper (optional)
– Dust mask (optional)
– Soft cloth
– Paintbrush
– Antiquing solution
– Cast iron paint
– Clear varnish

STEP 1

Lay any decorative piece of cast iron flat on a sturdy surface. Using the claw end of a hammer, ding random locations on the cast iron until you have achieved a rugged, uneven pattern. If you prefer a less rough-hewn patina, run a piece of fine-grit sandpaper across the cast iron to create more subtle blemishes. Don’t forget to wear a dust mask when using sandpaper so you don’t inhale any fine metal shavings.

STEP 2

Wipe off any metal dust from the cast iron with a soft cloth.

STEP 3

To complete the look of a realistically rustic cast-iron surface, apply store-bought antiquing finish or a few coats of cast iron–friendly paint, followed by clear varnish.

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Would you wear and use a vintage pocket watch?

Friday, January 29, 2010

How to “Age” Brass and Copper

How to age copper

A DS original piece created using multiple brass patina and rusting techniques.

  1. Pour some vinegar into a plastic container and add a tablespoon or two of salt.
  2. Mix well.
  3. Put your pieces in mixture and let them soak for at least a few minutes.
  4. Remove the pieces and dry with paper towel.
  5. Place them on a cookie sheet and put them into a 450 degree oven.
  6. Monitor the change, which should occur in a few minutes.
  7. Remove the pieces and let cool.
  1. Soak your pieces in the solution for 1 hour.
  2. Place them on a dark non-greased baking sheet and into a 450 degree oven for 20 minutes.
  3. Take the the hot brass pieces from the oven and place them into the vinegar solution.
  4. Remove them from the solution in a few minutes or when the desired patina has been achieved.
  5. Shake them off, carefully! Let air dry.
  6. Use very fine steel wool to polish and create highlights as desired.
  1. For larger pieces, select a container (with a lid) that will hold your item.
  2. Place a smaller container (preferably glass) inside the bottom of your large container, and fill the smaller container with ammonia.
  3. Place the brass in the large container so it does not touch the ammonia (liquid ammonia will form spots on the brass).
  4. Seal it tightly.
  5. Monitor the piece daily and change the liquid ammonia solution every day to maintain potency; if you are environmentally inclined, you can neutralize the used ammonia with baking soda and water before disposing of it.
  6. Remove the brass when you are happy with the finish.

Whatever method you decide to try, after the brass has the patina you want and has dried thoroughly, a coat or two of varnish or matte lacquer sealant will help maintain the color you worked so hard to achieve. Otherwise, the patina will continue to develop as the brass is exposed to oxygen in the air. Remember to seal the front and the back of the piece.

A footnote from a recent experience — I was using white wine vinegar and salt on a couple of pieces of what I thought was copper; that particular vinegar changed the metal to a green finish within mere minutes. If I had rinsed the piece when it had reached the desired color, it would have been fine, but after several hours the metal had changed to many odd colors including pink. I could speculate about the actual metal content of the piece, but on a separate try, I then discovered how to to stop the process and keep the finish.

Sprinkle dry baking soda on it, rinse it carefully, then pat it dry without wiping; this stops the development and once the metal dries, you will still have a nice verdigris on the metal (at least I did) and the acidity will be neutralized.

Aged copper displays a protective layer of rich blue-green patina, also known as verdigris. Rather than waiting the five to seven years it takes for new copper to naturally develop a patina when exposed to the elements, you can get that look now. A lovely patina is possible through the use of a patina kit or homemade concoctions.

The Patina Look

The patina that grows on aged copper is the result of exposure to the elements, especially areas close to saltwater. Salt in the air, combined with water and oxygen, reacts with the copper metal through oxidation. The reaction changes the metal surface by forcing some of the copper molecules to bond with oxygen, salt or other molecules. Compounds that make up verdigris include copper sulfate, copper carbonate and chloride salts. Copper sulfate is a bright blue-green color and gives most verdigris its beautiful color.

Create a Homemade Patina

Start by washing the copper with mild dish soap to remove all oils that may resist the patina. A little baking soda rubbed into the copper along the grain helps scrub away microscopic particles. After rinsing, soak the copper in a 1-to-1 ratio of white vinegar and salt in a small bowl for half an hour. The wet copper is placed on a towel to air dry. Crafters may sprinkle a small amount of salt on the wet copper to encourage the patina to develop. This process may take anywhere from a few hours to a few days to develop.

Use a Patina Kit

A patina kit puts patinas of a variety of colors, including the traditional blue-green, red, brown and black, on new copper within a few hours. Before applying the patina, clean the copper thoroughly with a cleaning pad and an abrasive. Rinse the metal with clean water and dry. Find both acid-free hot application patina kits and acid-containing cold application patina kits in stores. Apply the patina with a brush, sponge or roller. Place it in indirect light for two to three hours while the patina develops.

Warnings

Working with a commercial patina kit that contains acids may be hazardous. Wear protective rubber gloves, mask and safety glasses during the application process. Work outdoors, under a ventilation hood or in a well-ventilated area, to avoid inhaling acid fumes. Hot application patina kits require the use of a heat gun to warm the metal, which could cause burns to the skin. Treat the patina carefully; it is softer than the copper and can flake off easily. A coating of clear polyurethane spray helps protect the patina on finished projects.

The natural or chemical oxidation of copper creates a variety of shades, from black to bright blue-green, on its surface. Savvy crafters can purposely oxidize their copper jewelry and projects to achieve a beautiful antique look.

Cause of Oxidation

Oxidation is a naturally occurring process wherein copper loses electrons to oxygen or other molecules. This changes the copper surface into verdigris, which is made up of a number of compounds, including copper oxide, copper carbonate, copper chloride and copper acetate. The surface layer eventually covers and protects the rest of the metal underneath. There are plenty of other oxidizing agents that can affect copper.

Materials for Oxidizing Copper

Bowls, towels, bags and utensils are some of the tools you need to oxidize copper. The ingredients for the process can vary, because there are many oxidizers that react with the metal. Egg, salt, vinegar, ammonia — and commercial products, such as Liver of Sulphur. These ingredients are used in different ways to speed up the natural oxidation process that occurs when copper is exposed to the air and water.

Oxidizing Pennies with Vinegar

As a simple project to test out the process, use vinegar and salt to oxidize pennies. Mix up a solution of white vinegar and salt in a bowl. Place pennies in the bowl for several minutes. While in the bowl, the dull pennies will start to brighten up as their copper oxide layer is removed. Take the shiny pennies out of the salt and vinegar solution and place them, still wet, onto a paper towel. Leave them out overnight to get mild results — they should develop a verdigris patina. Soak the paper towel in the salt and vinegar solution, and place the pennies on it for up to a week to get more intense results.

Protecting the Patina

Verdigris is not as durable as copper, so it may need some protecting to preserve the layer. Very thick layers of verdigris can flake off of the copper in spots when washed, so rinse copper gently. Pat the item dry, and allow it to air dry until it’s completely bone-dry. Consider applying a light coating of clear polyurethane spray to help protect jewelry and other crafts. This coating may also help enhance some of the blue-green patina.

A vivid verdigris tone can cover any paintable surface, thanks to a two-part paint application. The base paint contains copper bits, so any item can have this rich look. And oxidizer turns the paint the color of patinated copper.

Step 1

Apply The Copper Surfacer

Photo by Lisa Shin

Mix the copper surfacer well to ensure that the metal particles are evenly distributed. Apply a thin coat using one of the foam brushes. Let dry (about an hour) before applying a second coat. Repeat until the surface has an even coverage of copper.

Step 2

Apply The Patina Solution

Photo by Lisa Shin

While the final coat is still tacky, use the second foam brush to apply the blue patina solution, making sure to wear protective gloves. Use liberally for a more overall blue color or sparingly for a more nuanced blue patina.

Step 3

Add More Solution

Photo by Lisa Shin

The color will start to change within 10 to 15 minutes. Add more solution for a greater color change; if the surfacer is no longer tacky, brush a new coat on the parts you’d like to color, and reapply the solution.

Step 4

Add More Surfacer

Photo by Lisa Shin

Once dry, you can add more surfacer with a sponge brush if a less overall blue look is desired.

Step 5

Apply a Sealer

Photo by Lisa Shin

For outdoor use, coat with a sealer, which will halt further oxidation of the surfacer.