Top Job Profiles Welcome to the World of P atina

While creating a patina finish requires careful attention to detail, developments in patina By Rachel Squires Associate Editor products continue to make the process easier.

ho doesn’t love a patina fin- Chemical Corp. says that patina has the cold process than simply applying ish? It protects while become a popular choice for finishing a chemical. While heat is no longer Woffering a lively variety of for two reasons. First, patina finishes necessary, it is still a very meticulous colors. A patina occurs when metal create a more natural and attractive project, requiring careful timing and oxidizes or changes color. This process look. Secondly, developments in patina attention to detail. is a product of natural or products continually make the forced exposure to acid. The classic example process easier. Three basic steps is the green color takes on with For example, it’s no longer neces- But no matter which process, there age. Although a natural patina may sary to use heat when applying patina are three basic steps to patinating met- take several years to happen, patina chemicals, or what patina specialists als: clean, apply, and protect. But chemical suppliers offer products that refer to as the hot process. Although it what’s the most important step? give the fabricator more control over may take longer for the cold process to According to Sur-Fin’s Dave and patination. Such control speeds up the produce the desired color, it requires Solomon Motamed of Triple-S process to a matter of weeks, days, and less equipment, like a torch. But the Chemical Products (both of their com- even hours in some cases. This is same beautiful patina finish can result. panies are located in Los Angeles, referred to as forced patination, and You simply dip, brush on, or spray on CA), the most important step in pati- there are several options available to a room-temperature product and the nating is the initial cleaning of the even the lay patinator. chemicals make the patina happen. metal. If the metal surface is not prop- Chaitanya Dave of Sur-Fin Of course there’s more involved in erly cleaned from the get go, oils or

1 FABRICATOR January-February 2002 dirt on the surface inhibit the reaction of the patina.

Step one – cleaning Ron Young of Sculpt Nouveau, Burbank, CA, says either sandblasting or using a good metal cleaner are the best ways to properly prepare metal surfaces. Sandblasting abrades the sur- face, which is necessary if it is highly polished. Young says, “When working with iron, steel, or aluminum you may need to remove and fire scale.” He also warns that although mild acids are available for cleaning, they can some- times interfere with the patina reaction. When using a metal cleaner on bronze, , or copper, Young sug- gests applying the cleaner with a brush, sponge, or rag. Let it stand for about five minutes. Then rub it with a red or green “Scotch Brite,” and rinse it with water. Repeat if necessary; dry the sur- face, and then apply the finish. When working with iron, steel, or aluminum, Young says to use the same steps but do not rinse the cleaner with water. Instead remove it with a cloth and then apply the finish immediately. Note that most companies that supply patina fin- ishing products also supply metal ABOVE: Vega Inc., Durham, NC, entered this bench with patinaed brass cleaners and conditioners. and copper flower accents in the 1998 Ernest Wiemann Top Job Contest. RIGHT: Art’s Work Unlimited , Miami, FL, applied a patina wash to tone down the bronze Step two – applying paint, and gold and copper brushing on this 2000 Top Job entry. But you can only prepare a metal surface so much. Some surfaces react process of patination when working reduces your color choices to varia- differently to acid applications. with metal coatings. tions of rust and white. However, Products like metal coatings and Once the surface — whether true adding a chemical called selenium to a provide a solution for applying metal or metal coating — is properly patina formula yields dark rust like patinas to surfaces that traditionally prepared, cleaned, and thoroughly black or grey on ferrous metals. don’t accept patina or are difficult met- dried, it’s time to apply the patina. Working with bronze, brass, and als to work with. Metal coatings can be Which patina chemical to use depends copper leaves you with a much wider applied to just about any non-metal on the kind of metal surface you are variety of possible colors, from green, surfaces or to metal surfaces when you working with and the color or finish to blue, to violet, and so on. Since there want to protect the metal underneath or you’d like the end product to reveal. is no iron in these metals they do not change the type of metal for finishing. There is a big dividing line between form rust. But, according to Debbie Once the coating is in place fabricators ferrous metals, which are iron, and and Ron Young, even an experienced can then treat the coated surface like steel and nonferrous metals, which are patina applier may find it difficult to that particular metal — with a few brass, bronze, and copper. It’s impor- create certain colors on nonferrous exceptions of course. For example, tant to understand that a patina is a metals. It takes a skilled eye and care- when applying patina finishes, Young chemical reaction that causes metals to ful handling of the metal and chemi- says to first apply a primer to a metal oxidize. This oxidation yields different cals. To make this process easier and to coating to keep it from being absorbed. colors with different metals depending increase the variety of possible colors Apply the primer “as soon as possible on the chemical formula applied. for ferrous metals, Ron Young created after cleaning because oxidation forms Typically, the of metals contain- special patina oxides. Since the prod- very quickly, even though you can’t ing iron, ferrous metals, is rust, while uct is already an oxide, the color, so to see it,” says Young. He also stresses aluminum forms a white oxide. So speak, is already produced. By apply- the importance of only using a cold working with these metals greatly ing it to the metal surface, you are

2 FABRICATOR January-February 2002 actually applying an oxide, not a pati- na. The patina has already happened, Definitions from Contemporary Patination and the color or oxide binds to the by Ron Young: metal surface without reacting to it. As mentioned, the patina process Patina: The color of the surface of the metal caused by weathering or itself, whether applying an oxide or a chemical application of acids. traditional chemical patina formula, can take up to several weeks before the Cold Patina: A process of applying patina chemical solutions directly final desired appearance is achieved. It to the unheated surface of the metal. Usually cold patinas are layered may take a variety of formulas and patinas involving cycles of applications lasting days or weeks until the multiple layers to produce a certain desired color is developed. color. Some formulas require dipping, brushing, or spraying. Jeremy Hot Patina: The most widely used technique. The surface of the metal Bonaguidi of Patina Finishes and is heated with a torch to open pours, usually around 200°F. Then the Copper Coats Inc., San Diego, CA, patina chemical solutions are applied with a brush or spray. As the warns fabricators to be careful during metal cools, the patina is locked in. application not to create puddles where the formula will be thicker in some Torch: An instrument for bringing together and properly mixing areas. According to Bonaguidi, weath- and gases so that when ignited, the heat of the flame is controlled. er temperature and humidity also affect the patina reaction. He says, “Do not Ferrous: A word used to describe compounds that contain iron, from apply in direct sunlight or excessively the Latin word ferrum for iron. hot weather, or during freezing or rainy weather.” Also be sure to allow each Oxide: A naturally occurring agent that causes the surface of metal to layer the appropriate amount of drying change color. time before applying another layer or before sealing the patina with a clear author and editor Danielle A. Doiesz patina would wear off from touching,” coat. Depending on the product you are explains why the demand for pre-pati- says Hunt. “It’s very tenacious to envi- using this can take from 24 hours to six nated copper roofing is on the rise - it’s ronmental attacks, but certain acids or eight days or longer. already done. However, David Hunt, will destroy it, and abrasives wear it.” Manager of Architectural Services at Keep this information in mind when Step three – protecting Revere Copper, says that although offering patina finishing to your Once you’ve achieved the look you Revere produces pre-patinated copper clients. It’s another reason why pro- want, seal it. Sealing your finish pro- sheets, there’s no been demand for pre- tecting a patina with some form of tects it from further weathering. patinated stock material. clear coating is so important. And it Ferrous metals may still rust and non- “Typically, we only produce pre- may require including a maintenance ferrous metals may . Your best patinated sheets up to 2 milliliters thick fee in contracts involving patina work. bet is to apply a clear coat. Young sug- for a sheet ounce weight,” says Hunt. But Motamed of Triple-S Chemical gests spraying on your clear coat rather “The reason is that there simply isn’t a says the reason ornamental and miscel- than brushing it on since the brush can market for anything else yet. Perhaps laneous fabricators aren’t really inter- create bubbles. He also says that two or there could be. But gates and rails are ested in pre-patinated materials is three light coats are better than one subject to a lot of ‘physical abuse,’ because they like to have more control heavy coating. Depending on the type which natural patination and pre-pati- over their projects. This said, as the of patina, you can also apply a layer of nation materials aren’t really that versatility of patina products increases, wax, either alone or in addition to the resistant too.” He explains that patina fabricators will have even more control clear coat is not resistant to abrasion. “If a door is over the finished look of their metal Aside from patina formulas, hot and sheathed with patinated copper, the creations, and that’s good news! cold processes, and oxides, there are other options for achieving a patina look, like patina paints and dyes. They come with their own application speci- Free Patina Technical Advice fications. Sur-Fin Chemical Corp* • (800) 282-3533 Another choice may be optimal for Triple-S Chemical Products* • (800) 862-5958• www.ssschemical.com some fabricators — pre-patinated cop- Patina Finishes and Copper Coats • (800) 882-7004 • www.patinafinishes.com. per materials. In an article published in Instructional Videos and Books (Obtaining these items have incurs a fee.) the summer 2001 issue of Architectural Sculpt Nouveau (760) 432-8242 www.sculptnouveau.com Metal, “Pre-patinated Copper Offers * Indicates NOMMA member. the Beauty of Aged Copper Now!”

FABRICATOR January/February 2002 3