How to Clean & Polish Copper

Though not considered a precious metal, beautiful copper is of enormous value around the house—especially for the way it handles heat. Copper is an excellent insulator, and it expands and contracts minimally in response to fluctuating temperatures, making it well suited to plumbing and cooking. But as anyone who’s ever seen an old penny knows, copper’s rich orange-gold gleam can easily turn dull and dark, even taking on a chalky greenish cast, when exposed to oxygen and the elements.

Moist conditions can contribute to tarnishing, but considering that copper is commonly used in pipes, sinks, gutters, and pots and pans, there’s little chance of reducing its exposure to water. Read on for bright ideas to clean all the copper in your home.

Copper Cleaning: General Rules and Caveats

Some folks appreciate the patina copper obtains with time, while others prefer that shiny-as-new appeal. But even if you like the look of a bit of age, some of what accumulates is just plain dirt. Fortunately, copper cleans up easily, often with natural ingredients you no doubt already have on hand in your pantry.

Care must be taken, however, because copper will scratch with overzealous scrubbing. Plus, any copper piece with a high-gloss finish that hasn’t changed color over time has likely been treated with a protective lacquer. These items should only be cleaned with dish soap and water, as even a mild acid can damage the sealant.

Keep the following general rules in mind when purging dirt, grime, and tarnish from copper:

• For a food-safe, all-natural DIY copper cleaner, mix a mild acid (such as lemon juice or distilled white vinegar) and a gentle abrasive (e.g., salt, flour, baking soda, or cream of tartar). Aim for a paste-like consistency that will stick to the copper surface, rather than a watery one that will run off.
• To avoid scratches, apply your homemade cleaning paste with a soft cotton cloth and buff in the direction of the grain, either up and down or left to right. Only resort to small circular motions when working to remove an especially tough spot.
• After cleaning, always rinse copper thoroughly with water and then dry with a fresh, soft cloth.
• Defer further tarnishing after cleaning by applying a small amount of mineral oil to the entire surface.

How to Clean Copper Cookware

Copper pots and pans (usually lined with a non-reactive metal such as stainless steel) have superior thermal conductivity that quickly and evenly distributes heat. If you invest in copper cookware—it is pricy!—you’ll want it to look its best.

To clean and restore shine, prepare an acid-abrasive paste in a bowl and slather it onto the copper surface.

Give it a few minutes of dwell time, and then buff with a soft cloth, rinse, and dry. In a pinch, rely on the acid in tomatoes to effectively clean copper. As ketchup or tomato paste, it’s already at the ideal consistency. Just rub it in with a clean rag, let sit briefly, then polish, rinse, and dry.

Tackle badly tarnished spots and the blackened bottoms of copper cookware with the baking soda. Sprinkle it on the area and work in with a damp soft cloth or sponge. A little elbow grease is fine but don’t be too aggressive or you’ll invite scratches.

Heat can help banish truly stubborn tarnish. Boil a cup of vinegar, a tablespoon of salt, and three cups of water in a large pot and add the copper item.

Let it boil until the tarnish begins to come off, then remove the item, let it cool, polish, rinse, and dry.

How to Clean a Copper Sink

Rustic charm isn’t the only attractive attribute of a copper sink. Copper has natural antibacterial properties, helpful in killing bacteria, so it’s a smart choice in the kitchen or bath. Manufacturers encourage letting a copper sink develop a deep, unique patina for a “living finish,” though some people do opt to coat the sink with beeswax to slow the process.

Daily cleaning of a copper sink simply involves washing it down with dish soap and water and a soft cloth (no scratch-producing scrubber sponges or scouring powder. Remember to rinse and dry the sink after use. Generally, wash dishes promptly rather than letting them soak, and wipe up drips of toothpaste and cosmetics that land in a bathroom sink, as agents in some products can dull the copper.

How to Clean Copper Plumbing Pipes

While cross-linked polyethylene (PEX) has become a material of choice for plumbing, copper pipes were used in ancient civilizations and are still prized today. Copper’s insulating qualities keep hot water hot, its antibacterial nature maintains drinkability, and its corrosion resistance means there’s little likelihood of leaks. If properly maintained, copper plumbing can last 50 years or more.

Though copper is highly resistant to corrosion—the deterioration of metal due to chemical reactions between it and its environment—there are circumstances that can cause copper pipes to corrode.

These include particularly low or high water pH levels, sand or sediment in the water, and/or improper plumbing installation. Cleaning copper pipes will neither cause nor stop corrosion. (This video with This Old House plumbing expert Richard Trethewey fully explains corrosion causes and prevention in copper plumbing.)

Copper plumbing may be especially prone to tarnishing at the joints, but the entire surface of pipes can start to look shabby over time.

To clean, first wipe the pipe with a rag to remove condensation, then treat with your homemade cleaner. If it fails to clean to your satisfaction:

• Carefully rub stubborn spots with an emery cloth, which is more flexible than sandpaper.
• Dampen a rag with acetone and wipe pipes to clean. Follow with soap and water, rinse, and then dry.
• Although calcium, lime, and rust can accrue on copper pipes, most popular commercial removers for this buildup are not suitable for copper—the chemical agents could damage the finish and possibly cause pitting.
• To get rid of grime, rust, and hard water deposits inside and outside of pipes, dismantle them and let them sit in a large plastic bin filled with distilled white vinegar for at least 15 minutes. Use a cotton rag to work off any tough spots, then rinse and set pipes upright on a towel to drain.