Things You'll Need
Instructions
 
Wash your sculpture with a soapy solution. Rinse it thoroughly and allow it to dry. 
Put your sculpture in an area protected from snow, rain, hail and wind. Placing it near a wall will suffice. 
Put the sculpture away from plants with vines. Observe the possibility of animal feces and sap and move your sculpture away from these areas. 
Coat a thin layer of beeswax over your sculpture with a horse comb or your hands. This will repel weather damage and preserve the metal.