copper sinks use and care

What you need to know

Copper sinks should be made of lead, mercury and arsenic free copper. Even a fraction of a percent of lead, mercury or arsenic can be dangerous. Copper is a chemical element with the symbol Cu (Latin: cuprum) and atomic number 29. It is a ductile metal with excellent electrical conductivity in its pure state and has a pinkish luster which is (beside gold) unusual for metals which are normally silvery white. It finds use as a heat conductor, an electrical conductor, as a building material, and as a constituent of various metal alloys. When recycled, copper can mix with the other metals that it may have been associated with. For instance: If copper wire is melted down, and the wire was originally used where the connections were lead soldered, there will be lead in the recycled copper unless significant and very expensive steps are taken to remove the lead. We are unaware that there are any governmental regulations that test imported sinks for lead and mercury. For your safety, please do your homework. 

 CLARIFICATION: Please keep in mind, 99% of all copper sink companies cannot legally claim their sinks are antimicrobial. The company must have an E.P.A. registration and be in compliance with all Federal regulations. Making any mention of antimicrobial benefits or claims on a website without the above compliance is against Federal law and fines have been known to be levied as high as $50,000 as told to us by the Copper Development Association.

Buying a copper sink is not an easy task these days. Sinks arrive daily from third world countries using recycled copper from questionable sources. That being the case, how does one choose a copper sink that is safe? First, consider a copper sink that is made in the USA. Generally speaking, these sinks will be made of copper that is certified to be lead and mercury free. Secondly, make sure you see something in writing indicating the copper is lead and mercury free. Make sure you look for the use and care section for each company. Lastly, look for a long warranty. Most quality sink manufacturers will stand behind their products for a minimum of 10 years. Ask about a return policy if you are not satisfied with the quality of the product. We noticed some companies do not have easy to find contact information on their websites. That should be a red flag.

Never purchase anything on the internet with a check! You have no recourse if there is a problem. Always use a credit card. Your credit card company will generally give ample protection if you have been defrauded.

When looking at photos online, make sure you can see a large clear photo. Small photos can mask construction imperfections. Look for kitchen copper sinks withinteriors that have not been lacquered. A lacquered finish will not withstand the rigors of typical kitchen use. We have noticed that the majority of copper sinks coming from China are lacquered inside the bowl. Best yet, find a copper sink without a waxed finish in the bowl. A waxed finish will require regular maintenance. Look for a copper sink with an interior that has a medium coloration. That is the natural color of copper when it has been aged. If you are looking for a hammered copper sink, look closely at the hammering. A deep hammering on the interior of your sink will hold water and you will have to wipe out your sink after each use. Most importantly, talk to the vendor. Don't make a purchase without asking questions.

Buying a home with an existing copper sink.

If you are considering the purchase of a home with an existing copper sink you may want to have the homeowner prove that there is no lead in the copper sink. This issue can be exactly like the lead based paint problems of the past. There is mounting evidence that copper sinks are coming in to this country with lead in the copper. If you are buying a home with an existing copper sink, the burden of proof lies with the homeowner. If you are selling, be prepared to be asked for documentation! It is generally sufficient to have a statement in writing from the manufacturer indicating they use lead-free copper. The best insurance is to have the copper lab tested unless the manufacturer can give sufficient proof that they are buying lead free copper. China has had a long history with regard to lead

Quality issues with regard to copper sinks:

When considering a copper sink, look at the quality. If you are looking for a kitchen sink, the copper sink should be made of 99% pure copper of 16 gauge as a minimum if cold rolled, 14 - 12 gauge if annealed. (the lower the number, the thicker the material) The corners should be welded, not soldered. The copper should be certified lead, mercury and arsenic free. All domestic copper is delivered with "Test Certification Papers". These papers show the type of copper, the percentage of pure copper and any other metal bonded with the copper. A common copper alloy for manufacturing sinks in the U.S. is called C122. This alloy is usually 99.7% pure copper with the balance being pure silver. This specialty alloy is used when higher strength and annealing resistance is needed. C110 is considered pure copper, but is not quite as "Tig Weld" friendly and is softer than C122. If a company can not give you certification papers, be wary.

If you have the opportunity to view the sink prior to purchasing, bring a tape measure. The sink should be square and true. Measure the front to back dimension, diagonally corner to corner (inside), and the apron dimensions (if necessary). All dimensions should be the same at all points. Too often, copper sinks are built out of square. Look at the corners. Are all corners the same radii? Often the radii of the corners are different, causing the countertop fabricator significant problems determining which radius to use when cutting out for the sink. Lavatory sinks may be constructed of a thinner copper. Generally that will not be a problem due to the size of the sink. A lacquered finish on a lavatory sink is not as much of a concern as it is on a kitchen sink. A lavatory sink does not get as much wear and tear as a kitchen sink. A non lacquered finish, however, is preferred.

If you are looking at an apron front sink, look at the construction of the apron. Ask if the apron front is open on the bottom or the sides. Often photos are taken that hide this issue. The best and strongest apron sinks will be entirely closed. With little or no support, the apron can easily be bent in normal use. Since online photos rarely show a view that would give an indication that the apron is open or closed on the sides and bottom, you should ask!

Talk to your countertop fabricator. They have likely installed several copper sinks and can give you some guidance as to what brands they have had luck with and those they have had difficulty with. One such company reported that they had to grind the edges of an imported copper sink in order to make it true and square. They told us that three of the workers developed a skin rash due to working with copper with unknown impurities.

Ask for referrals from your dealer. Speak to a few customers who have had copper sinks. Ask them if the sinks drain properly and if the sink is easy to care for. Copper sinks, if produced properly, should be very easy to care for. Before you buy, read the use and care. Many copper sink companies recommend you dry the sink after each use. This is an indication that the finish on the sink is not natural and requires a significant amount of care.

Types of copper used in copper sinks:

Pure copper comes in different forms. Hard cold rolled copper and annealed recycled copper are the most common forms of copper used in copper sinks. Annealed copper is heated to a point where the copper remains much softer. A softer copper is easier to hand hammer, however may not hold its form as well over time. Hard cold rolled copper is much stronger and will be less likely to warp over time or during shipping. Cold rolled hard copper is 12.9 times the yield strength of annealed copper. Both types can be pure copper, however purveyors of recycled copper is notorious for claiming purity when there is no proof from independent labs.  Most copper sinks are made from recycled copper. All too often, scrap copper (first photo) is collected, ground up, then melted down (second photo). pile of scrap copperThis process, without significant and expensive refinement steps, will leave impurities in the copper as copper wire often has lead in the solder. In some third world countries, copper wire is burned until the coating is burned off, then used as recycled copper. This practice is not only bad for the environment, but allows for all sorts of impurities to get into the copper. Imported copper products should show independent and reliable testing indicating purity. Unfortunately, this is rarely the case. Merely stating purity on a web site is no guarantee.

Design issues:

Drain location and drainage is key! Do you want a drain in the center of your sink? If so, make sure the sink is slanted to the drain. Many copper sink manufacturers do not adequately slant the bottom of the sink to the drain, requiring the user to hand dry out the sink after each use. Some manufacturers offer right or left rear drains. This is a significant benefit for usability. The drain is not in the way when cleaning items and a rear corner drain allows for better storage under the sink. Poor sink drainage is the most common complaint with regard to copper kitchen sinks. Make sure you have insurance from the company that your sink will drain properly. Read the use and care section of the web sites. If you see wording that describes regular waxing or the fact that the sink should be dried after use, beware. Copper is a resilient metal. It will withstand quite a bit of abuse and will, with time, change back to it's natural coloration (a medium color).

Apron front sinks are most popular because they allow the user to get closer to the work area inside the sink. Under mount sinks generally have a large section of countertop in front of the sink making the user reach further to work. When looking for an apron front, or farmhouse sink, make sure the apron is not too thick as that will defeat the purpose. A thicker apron will force you to reach further to a work surface. The point of an apron sink is to allow the user to reach the work surface of the sink with ease.

Finish issues with regard to copper sinks:

The finish of a copper sink is vitally important. Some manufacturers offer a lacquered finish on the interior of the bowl of the sink. This will wear off in time. We recommend staying away from any kitchen sink where the interior of the bowl is lacquered. Many copper sinks coming from China are lacquered. It is fine to lacquer the apron portion of a copper sink.

The best finish for the inside of a copper sink is a natural patina, which is very low maintenance. A natural patina is a rich medium brown coloration. Copper will naturally turn, in time, to a rich medium brown - therefore, a disturbance to the patina will only be temporary. The patina will return in a short time. On the other hand, an applied patina that is not a medium brown, will not fare well considering the use a kitchen sink receives. We believe that virtually any unnatural finish on the inside of a copper sink will eventually wear off in spots, creating an unsatisfactory look that is very difficult to repair.

Contrary to some concerns, copper will generally not turn green in a kitchen sink. It takes 7 years for a copper exposed to the outdoor environment to begin to turn green.. If you are looking for a uniform patina in a copper sink, we suggest you rethink your choice. There is no way to maintain a uniform patina in a copper sink.

If you are considering a copper sink with no finish at all, raw copper, be patient. Natural copper will not age over night. This process can take several weeks to several months. Once the copper has developed a reddish brown (medium color) patina, the sink should be very easy to maintain and quite appealing to look at.

A hammered copper sink is chosen when a more old world look is required. Beware of so-called hand hammering that is done by machine. You can easily tell if a sink is hand hammered. There will be no pattern to the hammering on the copper. Deep hammering inside a sink can cause water to sit inside the dents. This may be one of the reasons why many copper sink manufacturers request that their sinks be dried after every use.

Lacquer and copper... Many copper sinks, especially those from China, are lacquered. Lacquer has its place with regard to copper finishing. Lacquer should be used on copper decorative products or on the apron portion of a farm sink. We strongly believe that lacquer should never be used inside a sink. There is no way the lacquer can withstand the high temperatures, cleaning agents and abrasions typically encountered when using a kitchen sink. Many companies do not tell you their sinks are lacquered in the bowl area. You must ask! You will likely find that these sinks have a warranty of one year.

Maintenance Issues with regard to copper sinks:

"Antimicrobial Copper surfaces must not be waxed, painted, lacquered, varnished, or otherwise coated. Routine cleaning to remove dirt and filth is necessary for good sanitation and to assure the effective antibacterial performance of the Antimicrobial Copper alloy surface. Cleaning agents typically used for traditional touching surfaces are permissible; the appropriate cleaning agent depends on the type of soiling and the measure of sanitization required. Normal tarnishing or wear of Antimicrobial Copper surfaces will not impair the antimicrobial effectiveness of the product." Credit:

Naturally Weathered Copper is constantly aging, therefore the occasional scratch will disappear in a matter of days. The scratch will patina naturally to match the rest of the sink making it virtually undetectable. There is no need to scrub the sink with harsh chemicals. If you leave a lemon or another acidic product inside your copper sink it will take the natural patina away leaving a pink mark. The pink mark will darken with time and will blend in with the interior of the sink making it virtually disappear. If you purchase a copper sink with a wax coating, you will have to wax your sink every few days and you should avoid using harsh cleaning agents. The wax coating will halt the antimicrobial properties of the copper. Many manufacturers suggest you dry your sink after each use. Read the use and care section before you purchase any copper sink. If you are planning on keeping the sink for several years, find a sink with a long or lifetime warranty.

Copper Sinks Price Issue:

The price issue is one that can baffle the most intelligent person. Pricing for copper sinks ranges from one end of the spectrum to another. Watch out for inexpensive copper sinks. We are all well aware, by listening to the news, that copper is very expensive. So how is it that some copper sinks seem to be so inexpensive? We have heard that at least two countries are using recycled copper from melting down discarded telephone wire. Yes, there is copper in telephone wire, but there may also be other contaminants such as lead, mercury and arsenic. If you consider the fact that these questionable sources are not paying for their raw materials, and the labor force works for pennies an hour, you can see why some copper sinks are so inexpensive. Copper sinks come in contact with food and with person. There should be NO lead in the copper used for manufacturing a sink. A quality manufacturer should be able to provide some sort of written documentation indicating 99.9% purity. Consider warranty, length of time in business, get referrals, and if you think the price is too good to be true... it usually is! Look carefully at written warranties. One company offers a warranty that details the customer must ship the sink back (to Mexico) for an exchange if the sink is defective. The consumer must bear the cost of the shipping to Mexico - possibly costing as much as the sink! In contrast, another offers a warranty that pays all shipping costs plus an additional $100 for your inconvenience. A good indicator of the degree of maintenance required for a copper sink company is to look at their use and care statement. Some recommend drying after every use. Some indicate no acids or abrasives should be used. Some indicate to simply wash with dish soap with no other requirements.

The bottom line... do your homework. A copper sink can be the most functional low maintenance sink you could invest in, or it could be a maintenance nightmare. It all depends on where you make your purchase. Please do not ask us for referrals, as we wish to maintain our neutral position. This is an informative web site only. If you have questions about use and care or any other generic questions, we will be glad to answer them for you. Email Us


We have had countless requests for recommending copper sink companies. We will not make any recommendations. We have also had several requests looking for copper sinks made in the USA. We have researched several copper sink companies and have found two companies who build their sinks in the USA. H.P. Austin and Rachiele. Rachiele is the only company that has shown certification papers indicating the copper they use is domestic copper in the manufacturing of their sinks. This may not be the complete list, but at the time we did our research, that was all we could find. We do not endorse either company. Be wary of companies that do not clearly list their address, phone number and warranty information.

This list has been prepared for use by consumers. We make no representation or warranty of any kind with respect to the companies, their products or services.

Resources: Copper Development Association      Antimicrobial Copper