Dry ice blasting is an evolving technology that uses dry ice pellets instead of traditional abrasive media to strip a painted before recoating. The unique characteristics of carbon dioxide are what make this blasting procedure so effective.
The by-product of dry ice blasting is carbon dioxide, the same gas that we exhale every time we breathe. With proper ventilation, a cleaned area can readied for safe use almost immediately.
Unlike steel grit or sand, which merely impact the surface and depend on friction to wear away the old paint or coating, dry ice pellets create a field of micro-explosions on the painted surface, which can speed up removal procedures. The rapid sublimation of the carbon dioxide from its solid to gaseous state causes it to expand to over 800 times its initial volume. The rapid sublimation forces carbon dioxide gas behind the paint layer, where it blisters away more of the paint as it continues to expand along the substrate.
Since dry ice is over one hundred degrees colder than water ice, the frozen pellets used in dry ice blasting lower the temperature of the work surface. As we all know, low temperatures negatively affect the adhesive qualities of paint and industrial coatings. Combined with the abrasive impact of the pellets, most paints don’t stand a chance.
The intense cold of the dry ice pellets can also cause the surface material itself to shrink underneath the paint layer, further weakening the integrity of the paint.