Copper Patina / Verdigris Contamination

Copper patina builds up as a stubborn green layer on exposed surfaces through long-term reaction with air and moisture, standing out from typical oxidations with its rock-solid adhesion that speeds up hidden corrosion below. It clings unevenly to reactive metals like copper, brass, and bronze, embedding deeply into the substrate and creating patchy films on nearby inert spots. Removing it poses a real challenge, as traditional methods often scratch or leave residue, but laser cleaning works out effectively by vaporizing the layer precisely to reveal a clean, original shine.