Throw an ice cube against a wall and it will shatter, perhaps denting the wall. But hurl a tiny shard of ice against a wall, and something different and unexpected happens: It acts as a coating remover. That odd behavior of ice shards could make them an excellent replacement for sandblasting and other abrasive methods in cleaning surfaces.
According to research commissioned by the Canadian Defense Research Establishment Pacific in the 1980s, the impact of an ice shard on a coated surface compresses the coating and melts the ice. The coating can then rebound so rapidly that it pulls itself off from the surface, allowing the melted ice to wash it away. Ice Blast International Corp. in Victoria, B.C., has commercialized the technology in a low-pressure system that can use as little as 20 gallons of water an hour, compared with up to 60 gallons a minute for a high-pressure water spray to cover the same area. The shards, about 1/8-inch across, also can remove burrs from metal surfaces. Ice Blast has linked up with machine-tool builder Utica Enterprises Inc. in Shelby Township, Mich., to use the process in deburring.