Bronze casting is a meticulous art form where even minor imperfections like gas bubbles can ruin a sculpture. Artists employ several techniques to prevent these bubbles and ensure a flawless finish.

First, proper wax model preparation is critical. Any trapped air in the wax will transfer to the metal. Artists use vacuum chambers or pressure pots to remove air from the molten wax before pouring it into molds.

During the investment phase, the ceramic shell must be carefully dried and fired. Rapid heating can cause steam bubbles, so a slow, controlled burnout process is essential to eliminate moisture and organic residues.

When pouring molten bronze, artists control the temperature and flow. Overheating the metal can release dissolved gases, while uneven pouring traps air. Skilled casters tilt the mold to allow air to escape and use vents or sprues to channel gases away from the sculpture.

Degassing agents like copper phosphide are sometimes added to the molten bronze to bind with dissolved hydrogen, a common cause of porosity. Additionally, centrifugal or vacuum casting techniques force bubbles outward or evacuate them entirely.

Post-casting, artists inspect for bubbles and may use welding or patination to disguise minor flaws. Mastery of these methods separates amateur work from professional-grade bronze art.