Almost all copper garden sculptures start as polished copper. To keep the polished copper shine, you must treat your copper. If not treated, polished copper will change to the most popular of all the finishes associated with copper, the classical vintage Patina look. It is the turquoise colored layer that is often desired with copper. Patina is formed by the natural chemical action of elements on the raw copper or bronze. Interesting thing about patina is that, apart from lending color, it also acts as a weatherproof protective coating which does not allow further action of the elements. Once this basic protection is achieved, you need not worry much about protecting the surface. All you now have to do is to dust and keep it clean. If you want to clean it with moist cloth, make sure that you do not use any harsh chemical. It may damage the patina and eventually eat into the statue. When using water to clean the statue, make sure that it is not acidic in nature as copper is one of the most reactive materials on earth. When patina of the statue is already there when you buy it, This is because various substances are used to bring the desired color of patina faster. This speed ageing patina will slowly change to a more natural turquoise patina if left alone.
If you want to keep the polished copper look, you will find copper shields at any local hardware store. You may want to first treat with a copper cleaner or polisher. Using supermarket copper polishes may work well enough, but professional polishes often produce better results. Check with a paint or hardware store for recommendations. Make sure to use a polish that is non-abrasive. Any cloth that you use should be 100% cotton, so as not to scratch the copper. Never use steel wool or metallic abrasives on copper - they may contain rust inhibitors that may turn the copper black. After clean and polishing your copper outdoor garden art, apply a copper shield for years of protection.