Brass

This alloy tarnishes quickly in open air, so many brass objects have been coated with lacquer to help maintain the shine. Avoid using abrasive pads or cleaners, since abrasion will remove the lacquer and the underlying, now-unprotected brass will tarnish in scratches and streaks. Use a mild detergent and gently wash lacquered brass with a soft cloth.

 

Untreated brass may simply be dusted, leaving the tarnish intact. Whether lacquered or not, don’t handle the object directly while doing so. You’ll leave fingerprints that can degrade lacquer or become permanently etched into untreated brass. Use a cream metal polish to restore the original shine to un-lacquered pieces, but don’t be too quick to do so if the object might be a valuable or historical antique – have a professional evaluate it first, since tarnish patina is a major aspect of historical significance. Most qualified conservators are able to evaluate such pieces, and some will clean them for you the proper way.

 

References:

 

Don Aslett, The Cleaning Encyclopedia: Your A to Z Illustrated Guide to Cleaning Like the Pros.

Jeff Bredenberg, editor, Clean It Fast, Clean It Right: The Ultimate Guide to Making Everything You Own Sparkle & Shine.