1. Is there anything that I should not put in my new copper sink?
That question is a loaded question with many answers. First of all, your sink must be natural copper, with no lacquer or waxes on it for the following information to be true. Technically, there are many items which will temporarily disturb the patina on a copper sink. Most foods are acidic and will eventually (if left for a period of time) remove the natural patina. This should not be of great concern. The patina will return on its own. The most common comment is regarding pots and pans. A pot or pan left in a copper sink may leave a dark ring in the bottom of the sink. This dark ring is caused by an acceleration of the patination process or a reaction of aluminum to the copper. This can be avoided by not leaving pots and pans in the sink. If, however, an aluminum pan is left in the sink, the fix is simple. In most cases, it will go away on its own. If you are in a hurry, just take a "ScotchBrite" pad and gently abrade the dark area until it lightens. Don't worry about making that area lighter than the surrounding area. The copper will naturally darken to match the surrounding area in little time.
If the interior of your copper sink has a lacquer on it, or baked into it, we have heard of several liquids, including bleach and hot water, that have permanently damaged the lacquer. There is really no option for repairing a lacquered interior that we are aware of.
2. Will my copper sink dent easily?
That all depends on the thickness and the type of copper. Thinner or softer material will dent easily. The type of copper is more important. Annealed copper (which can be pure copper) is soft and can dent easily. Cold rolled copper is very hard and is very difficult to dent. This type of copper is so hard, only an intentional hit will damage the sink.
3. Should I wax my sink?
Generally, you should not wax your sink on the inside at all. The wax will stop the natural antibacterial properties of the copper. If your sink is lacquered, follow the instructions given by the manufacturer.
4. Will bleach hurt my copper sink?
If the sink has no lacquer or wax on it, bleach will not hurt the copper. If you are not sure if your sink has a protective coating, do not use bleach. If there is a lacquer over the copper, the bleach can turn the lacquer a whitish color and can not be repaired.
5. How can I tell where my sink was manufactured?
Ask the supplier to tell you where the sink is manufactured. Make sure you get this in writing, or copy a page from their web site indicating that information. Some web sites are intentionally misleading viewers as to the origin of their sinks.
6. Is copper safe to use as a kitchen sink?
This is also a loaded question. Some copper sinks are indeed safe, some may be quite hazardous to your health. Pure copper is a natural antibacterial metal. It will require normal cleaning and removal of dirt and grime and must not have any coatings such as wax or lacquer which will eliminate the natural antimicrobial action of copper. There should be little concern at all about preparing foods in or around a copper sink. Remember, most homes had copper pipes for drinking water. One of the (then unknown) benefits of having copper water pipes, is that the copper was likely killing bacteria. Unsafe copper sinks are sinks that have small percentages of lead, mercury or arsenic. These are the three materials that can be found in copper when there is no controls over the purity. When you are told copper is 99% pure, you need to ask what the other materials are. 99.9% pure copper is not safe if the .01% is mercury! Again, get this in writing. An email from the supplier should suffice.
7. Does a copper sink scratch easily?
Well, copper will scratch, but the good news is that the scratch will not be noticeable in a few days - again, only if the interior surface is natural copper with a natural patina. Any scratch will age quickly and become virtually invisible. Stainless steel scratches easily too, but the scratch will never be unnoticeable. This is one of the significant advantages of copper sinks.
8. What color will my copper sink turn in time?
The image to the far left is polished copper. The pink tone is very unnatural to copper. Copper in a polished state is unstable. Merely touching it will cause the copper to turn brown due to the acids in your hands. The true natural color of copper is the second photo. Copper stabilizes through time by oxidizing the outer layer, which turns a medium to deep reddish brown. Take a look in your purse or pocket. Find an old penny. You will instantly see the natural color of copper. Now, you may have seen old buildings with copper roofing, or even the Statue of Liberty. Likely all of these are a greenish blue. Copper will turn this color only when subjected to the outdoor elements for a period of many years. The timeline for copper patination in an outdoor environment is something like this: First 6 months - the copper will start out a pink color (like a new penny) and will begin getting spots of brown. 6 to 18 months, the copper will become a medium brown color. 1 year to 10 years - copper will darken to a deeper brown. Only after 10 years will the copper start to show the greenish blue patina. It could take as long as 20 years for the copper to turn completely. That being said, a copper sink should never turn greenish blue, as the sink is constantly getting used and the top layer of the patina is getting removed. Even if the patina is entirely removed, it will "grow" back in a matter of days. If you see a copper sink that is unlike the coloration of the second photo, the coloration is unnatural. When you start to use the sink, the bottom (especially) will be abraded so that the original "finish" comes off and the copper begins to go through its natural aging process. That aging process will cause the copper to go to its natural color - the second photo. The overall look of the sink becomes unsightly and basically very difficult to care for.
9. I have seen nickel plated copper sinks. How well do they hold up?
There is no plating available that will last for many years on a copper sink. Normal use will cause the plating to rub off in high use areas. You should look at the length of the warranty. Our best assessment is that there is no nickel plated copper sink with a warranty longer than a few years.
10. Will hard water or well water affect my copper sink?
Hard water is actually the friend of copper. Hard water will accelerate the patina process due to the mineral content generally found in well water. If the copper sink has an unnatural finish or a lacquer finish on the inside of the bowl, hard water will likely leave calcium deposits if the sink is not dried after each use. Many imported copper sinks are not designed to drain fully, hence water can sit in the bowl for some time. Again, this is why it is suggested that you dry the sink after each use.