All About Polishing Valuable Metals

By Dennis Gaffney

Ernest DuMouchelle, vice president of DuMouchelle Gallery in Detroit and an appraiser for ANTIQUES ROADSHOW, has seen more than his share of valuable metals ruined. Routinely, customers bring him their prized candlesticks, serving dishes, statues, coffee pots, and goblets made of brass, silver, bronze, or pewter. Often, the pieces arrive damaged not by time or the elements, but by ignorance. Some owners have scoured these objects with steel wool or Ajax. Others have ratcheted up the assault by plugging in their drills, attaching a round, metallic brush to it, and then assaulting their pieces with a gusto only a power tool can muster.

Learn how to polish your valuable metals without ruining them

"These methods put little grooves in your valuable metals," Ernest says. And such scratches, he says, are not a good thing, since they can usually only be repaired by a specialist—and that, of course, costs money. We asked Ernest to provide some advice on when and how to properly polish your silver, brass, bronze, and pewter valuables. Here's what he said.

Saving Your Silver
If there is a golden rule in caring for your silver, Ernest says, it's that the easiest way to polish it is not always the best. That's why the Detroit appraiser recommends avoiding "instant dips," those high-octane metal polishes that promise faster results with less elbow grease. Such polishes achieve their quick results by adding more acids and abrasives into the mix, which only strip more of the valuable metal off of your prized possession each time you polish it. With only a few uses of an instant dip, it's possible to rub away the silver plating or even its identifying marks. In both cases, your piece is devalued. While it's possible to re-plate silver that's been rubbed down to its base metal, its an extremely expensive process that can also muddy the clarity of a piece's designs. "Instant dip" cleaners also pose another problem: if not removed properly, the products can leave a milky finish on your silver. And not only is that ugly, notes the Detroit appraiser, it's also difficult to remove.

Ernest suggests using gentler polishes made by reputable companies such as Wright & Company or W.J. Hagerty & Sons. "Any good hardware store and a lot of the supermarkets will stock the good products," Ernest says. These milder polishes force you to rub your silver a little harder and for a longer period of time. Just as a labor-intensive French polishing brings out the natural beauty of wood, Ernest notes, a slow polish brings out the natural brilliance of silver and other metals.

"You get a rich patina by polishing your pieces slowly," Ernest says. "Silver polished properly looks beautiful."

Polishing the Brass
Brass was also meant for polishing. "The only problem with brass," says Ernest, "is that sometimes it has been lacquered."

Lacquer, usually absent on antique pieces, is often added to more modern brass to protect it from the elements and keep it from tarnishing. Sometimes an owner will rub the lacquer, which often looks yellowish, off of the piece of brass. But once the lacquer is removed, the brass is vulnerable to oxidation. If owners want to keep a piece shiny, they have to do what soldiers have long done with their brass belt buckles and pins: polish them regularly. In the home, that means a polish every few weeks—more than most people are willing to devote to brass candlesticks and doorknobs. The alternative is to learn to live with and love duller-looking brass.

Wash Your Bronzes
A finish is usually put on bronzes by an artist or at a foundry to give the metal a darker patina or to shade the metal to accentuate its three-dimensionality. Sometimes bronze is even coated with gold. That's why it's best to avoid polishing bronzes. Doing so is like vigorously scrubbing the surface of a masterpiece painting. In both cases, you're removing a layer of the piece that the artist intended to be there.

Such damage diminishes both the integrity of your piece and its value. Ernest recently sold a bronze fountain by the American sculptor Harriet Whitney Frishmuth that had a value that would have dropped by $50,000 if the sellers had rubbed the patina off. Ernest and his co-workers simply washed the piece, which is recommended because bronzes don't corrode in water as do many other metals.

Your Choice on Pewter
With pewter, there's a debate among experts as to whether you should polish it or just let it age naturally. The question is an aesthetic one. Those who prefer their metals shiny, polish their pewter. Unlike brass, polished pewter is slow to oxidize and therefore holds its shine for years.

But Ernest and many other antique dealers prefer the dull gray finish and the metallic freckles that time puts on pewter. "I'm just one of the people who like the way it looks without cleaning," Ernest says. "In my opinion, it was meant to look a little gnarly."

So the big lesson is: When in doubt about how to polish your metallic valuable, don't just wing it. "It's always good to get advice," Ernest says. "If it's an important piece, you should ask a reputable antiques dealer or a museum curator." 

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