Creating metal sculptures that withstand acid rain requires careful planning and execution. Start by selecting corrosion-resistant metals like stainless steel, bronze, or corten steel, which naturally develop protective patinas. For other metals, apply specialized protective coatings such as powder coatings or marine-grade epoxy paints that create barriers against moisture and acidic compounds.

Consider the sculpture's design - avoid flat surfaces where water can pool, and incorporate drainage channels to prevent standing water. Regular maintenance is crucial; clean sculptures annually with pH-neutral solutions to remove acidic deposits without damaging protective layers.

For added protection, apply wax coatings (like automotive wax) every 6-12 months on bronze pieces, or use sacrificial anodes for large steel installations. Elevate sculptures slightly above ground level to prevent soil moisture absorption.

Artists should also consider local climate conditions - areas with heavy industrial pollution may require more frequent maintenance. Document all protective treatments used, as this information helps future conservators properly care for the artwork. By combining these strategies, your metal sculptures can maintain their beauty for decades despite exposure to acid rain.