Pewter is a metal alloy comprised of at least 90 percent tin. The remaining ten percent or less consists of lead, copper, or antimony. Older items made of pewter contain more lead and become tarnished more quickly, developing a dark silver-gray hue from oxidation, known as an antique finish. Modern pewter, while it does tarnish, develops a dark patina and is easier to clean than the older, lead-infused metal. Modern pewter pieces will have a satin or polished finish, and cleaning methods depend upon the finish.
Polished pewter is the most common, and has a shiny finish similar to silver. It is often mistaken for sterling silver due to its high shine. To clean pewter with a polished finish, first wash the piece in warm, soapy water with a clean cotton cloth or sponge, and then rinse and dry thoroughly.
Next, make a paste by combining one teaspoon (5 ml) salt, one cup (237 ml) vinegar, and ½ cup (118 ml) of white flour. This paste should be applied to the pewter and rubbed in gently using a clean cloth. After the application, rinse the piece in warm water and dry with a towel. This method will remove dirt and restore luster to any object with a polished pewter finish.
Satin-finished pewter is rougher in appearance and does not have a shiny finish like polished pewter. Instead, it is grainy and often darker in color. To clean pewter with a satin finish, first wash the object in warm, soapy water with a clean cloth or sponge. Rinse in warm water and dry thoroughly with a soft towel.
Next, buff the surface of the pewter lightly with steel wool, rubbing with the grain and not against it. Make sure to press only very lightly, so as not to damage the grainy appearance of the item. This method should be performed no more than once per year, as doing so more frequently could cause permanent damage to the finish.
Antique, or oxidized, finished pewter should not be polished in any way. To clean pewter with an antique finish, wash with warm, soapy water only as needed to remove accumulated dust and dirt. Rinse with warm water and dry thoroughly to keep the finish looking its best without causing damage.
Never put pewter into the dishwasher, as this can cause serious damage to a modern or antique finish. Do not use abrasive cleaners, jewelry cleaners, or household cleaners on pewter items. There are some commercial cleaning products on the market which are safe to use to clean pewter, however ensure that they are formulated for pewter and not for silver prior to use.