If you’re considering a metal faucet, sink, or countertop for your kitchen or bathroom, you may have heard the term “living finish” or perhaps “organic finish.” Any metal other than stainless steel that is not coated with a sealer or a metal finish like chrome will acquire a “patina” over time. This means that the finish will change and evolve through exposure to the environment. Some call this “oxidation” (exposure to oxygen), but this patina process is also caused by other environmental factors that the metal surface might come into contact with, as well as wear and tear resulting from regular use.
When applied to plumbing fixtures, the question most often comes up regarding copper sinks. Faucet and drain hardware manufacturers typically address this issue with certain coatings that protect the metal surface from the environment, thus preventing patina or changes in finish. However, these types of coatings (PVD or other types of clear protective finishes) are more difficult to apply to a larger surface area such as a sink and require a more “production” like manufacturing process. Therefore, many handcrafted copper and bronze sinks are not sealed and will have a true vivid finish.
Metal products with a chrome finish or stainless steel products are often called “non-living”. This is only partially true. In fact, the surfaces of these products can darken over time depending on the environment and the care given to them. We’ve also heard nickel referred to as a “dull finish”, but the fact is that nickel will also patinate or “tarnish”. However, this process is significantly slower than unprotected copper or bronze.
With unprotected brass, bronze or copper, the patina process occurs more quickly. What happens to the metal finish over time? The answer to this question depends on whether or not an artificial patina was applied when the sink was made, environmental factors present during use, how much the product is used (wear and tear), and the type of maintenance or care employed.
If you are purchasing a copper sink that is finished (i.e., not a “bright copper”), heat and/or chemicals have been applied to speed up the aging process. You’ll see terms like “oil rubbed bronze” or “weathered copper.” To create these finishes, the metal has been exposed to a chemical bath and possibly also to heat, which reacts with the metal and changes the color. The darker the finish, the less the metal will patinate or age after it is installed. In a way, you are “bogging down” the patina process. Regardless, you still have a vivid finish that will evolve, but in general, the darker the patina at first, the slower the change over time.
Environmental factors specific to your home and the chemicals your sink surface may be exposed to are the great unknowns. Every application and environment is different. Moisture, air salinity, pollutants and oxygen work together over time to coat metal surfaces with a characteristic patina. If you have a copper kitchen sink and you expose the metal surface to certain acids like those found in a lemon, it will actually dissolve some of the patina. The constant changes due to these myriad factors are appreciated by some and not welcomed by others. Personally, I like deep tones and earthy browns that appear over time. I see this as “character” and appreciate the uniqueness in color and tone between two identical products in different settings.
If you appreciate a lively finish, caring for and maintaining your sink will be fairly easy. If you want to avoid it, this is possible to a certain extent. There are several different ways to slow down the patina process. Applying a brass or furniture polish that does not contain polishes or cleaners can slow the change in patina in the same way that an auto polish protects your car’s finish. If you want, you can remove the patina from a sink with a metal polish or a mild acid, such as lemon juice or vinegar. Waxing the surface will preserve the shine, or the sink can be left untreated to develop a new patina.
We often feel that our clients fear a lively finish…or that this type of finish will require more maintenance. Our answer is always the same: if you don’t like the patina you finally get, you can always start over! Any copper or brass cleaner will reverse the patina to a shiny surface if desired. If left unprotected the aging process starts all over again and within a few weeks you will start to see the surface of the metal darken. Also, you can always buy a sink with a darker finish and keep the surface waxed. This will ensure the fewest changes over time. As far as maintenance goes, the occasional cleaning with soap and water is really all you need to do. If you choose to wax your sink, this is generally something you’ll need to do only every 3-6 months, depending on the amount of use. You can read more about the care and maintenance of copper sinks at Copper Sinks Online.