How to remove white spots from a copper teakettle

Q:I think a copper teakettle was mistakenly washed in the dishwasher. Now it's covered in white spots. How do I get them off?

Alexandria, Va.

A:The white spots are almost certainly cloudiness in a lacquer coating that the manufacturer of your teakettle applied to keep the copper shiny and bright for as long as possible.

Lacquer coatings are great on purely decorative pieces that owners don’t want to develop a patina. But this coating is not appropriate for teakettles or pots that are used for cooking, because the lacquer does not stand up to hot water. The finish develops white patches, and small areas of tarnish eventually develop, causing the metal to become splotchy. The combination of bright copper with patches of tarnish is far less attractive than copper with a more even patina.

“The white spots are very common to lacquered copper that is exposed to steam,” said Teri Rosvall, owner of Copperton Lane Antiques and Collectibles (208-547-7313; coppertonlane.com), a Utah-based company that specializes in antique and mid-century copperware. “A dishwasher would definitely do that,” she wrote in an email after looking at the picture you sent.

How can I seal the open knockouts in my electrical boxes?

Wood furniture with a lacquer coating can develop white spots because of contact with moisture. The moisture gets trapped within the lacquer, leading to a cloudy look. And it can cause tiny cracks within the finish, which means the spots remain visible even if gentle heat is applied to evaporate trapped moisture. A similar dynamic is probably happening within the lacquer of your teakettle.

But just as with a wood finish that has become cloudy, there is a surefire way to get rid of the white spots on your kettle: Remove the lacquer coating.

Rosvall recommends using a lacquer remover sold with other solvents in paint stores only as a last resort. It’s usually possible to simply immerse a piece such as a teakettle in boiling water with baking soda. (She suggests using one tablespoon of baking soda per one quart of water.) If you don’t have a pot large enough to submerge the whole kettle, use tongs and immerse the pot one section at a time. A canning kettle used for boiling filled jars would be ideal, because there is never direct food contact, so you don’t have to worry about any residue that might remain once you loosen the lacquer.

“When you notice the lacquer peeling off, or a clear scum rising to the top of the water, take the piece out and immediately scrub with a soft cloth or sponge and copper cleaner or polish of your choice,” Rosvall suggests in the “Copper Care” section of Copperton Lane’s website. She uses Wright’s Copper Cream ($6.99 for an eight-ounce container at Ace Hardware).

Why do my new faucets produce less water?

If the coating doesn’t completely come off, repeat the process. You can do it multiple times if needed.

If baking soda in boiling water doesn’t work, lacquer thinner from a paint store almost certainly would. Follow all safety precautions listed on the label. Test in an inconspicuous place first, and work where there is plenty of fresh air and no open flame. Lacquer thinner is a powerful solvent, and both the liquid and the fumes are flammable. If you can’t work outside, wear a half-face respirator fitted with an organic vapor cartridge. A disposable respirator will not protect you from inhaling the fumes, which can cause lightheadedness in the short term and brain and lung damage with high, prolonged exposure. Also avoid skin contact by wearing chemical-resistant gloves.

Once the lacquer is off, you can decide how you want to maintain your teakettle. If you want a shiny copper look, you’ll need to polish it regularly. (Without a splotchy coating in the way, this job should go by quickly.) Or you can let the copper develop its natural, dark red patina, which makes even relatively new kettles look like vintage pieces. If you need to clean off spattered food, don’t use steel wool, powdered cleanser or even homemade concoctions, such as lemon juice and salt. All of these, even the salt, can scratch it, Rosvall says. But she says sprinkling on baking soda and rubbing with a soft cloth works well and has no downside.

The picture you sent shows that your teakettle is silvery on the interior, which is good. Copper used for cooking or heating water should be lined, because acids can leach copper into foods, which makes the food unsafe to eat. Lining the copper prevents direct contact but doesn’t interfere with one of copper’s great qualities: It heats up quickly and evenly. Copper cookware used to be lined with tin, but tin melts at about 450 degrees Fahrenheit, a temperature easily reached when an empty pan is left unattended. Although it’s possible to have a damaged pan relined, few towns have a shop that offers this service. Most modern copper cookware is lined with nickel or stainless steel, which are more durable.

More from Lifestyle:

How can I seal the open knockouts in my electrical boxes?

How to deal with plaster bubbling up on the inside of an exterior wall

Why do my new faucets produce less water?