NASA, USBI Technology Hits The Roof

The Convergent Spray Technologies™ (CST™) spray process, developed by USBI Co. and used by NASA's Marshall Space Flight Center (MSFC), both located in Huntsville, Ala., to apply heat-resistant coatings to the Space Shuttle's Solid Rocket Boosters, has been found to be suitable for yet another down-to-earth application - that of applying a new coating to the metal roofs of buildings.

USBI is a NASA prime contractor on the Space Shuttle Solid Rocket Booster Program, a wholly owned subsidiary of United Technologies Corp., and part of Pratt & Whitney Space Propulsion.

A recently completed MSFC/USBI project demonstrated the feasibility of applying the space-age technology to the roofing industry. This was accomplished by producing an environmentally compliant coating that used recycled materials, a CST™ spray process portable application cart, and a hand-held applicator with a CST™ spray process nozzle. The project culminated in the application of a coating to a 960 square foot metal roof at the Marshall Center.

The project was executed in three phases. The first involved independent research and development experimentation with materials, formulations and the CST™ spray process. In phase two, the coatings were tested and the spray process was refined. Coatings were applied in two field demonstrations as part of the third phase. Funding for the latter phases was provided by the Environmental Protection Agency under the Environmental Technology Initiative.

The project began with a survey of the roofing industry to determine how a CST™ spray process might best serve the market. Various environmentally friendly paints, coatings and filler materials were studied and tested. Hand mixes, sprays and various supplemental materials were tested by the NASA and USBI engineers in making their final roof coating selection.

Two selected base coatings were tested with a filler material made from finely ground rubber tires to learn the best way to apply the coating. This is the third use NASA has developed for worn-out automobile tires. A cryogenic recycling process developed at the Stennis Space Center in Mississippi is helping to convert thousands of worn-out tires into road paving material and garden hoses.

As for the newest use as a roof coating filler material, a demonstration coating was applied to a portion of the roof of a building at the Marshall Center last August. The coating was sprayed over both the galvanized steel/aluminum-painted substrate and over a foam insulation surface on the same roof. In April of this year, a coating was applied to the roof of a section of a second MSFC building. Real-time wear, performance, and resistance to weather of the coatings are being monitored.

John West, NASA engineer on the project, said researchers hope their work will result in a fast, easy, environmentally friendly spray-on coating process for the roofing industry. Tests have shown the coating to have satisfactory moisture resistance, adhesion properties, tensile strength, flexibility, resistance to water vapor penetration, and resistance to the cyclic effects of aging, rain, dew, and ultraviolet radiation (sunlight) exposure.

The application of CST™ spray process to roofing is its second down-to-earth application. Earlier this year, a spray process derived from the CST™ was successfully used to apply a skid-resistant surface to a portion of a highway bridge deck south of Huntsville, and to a portion of Alabama Highway 90 in the Bankhead Tunnel in Mobile.

The I-65 bridge deck's coating was applied in less than one hour. Four hours after the application was completed, the roadway was reopened to traffic. This is a fraction of the time such a resurfacing would normally require. In addition to being faster, the cost of this method of resurfacing may be significantly less than would be the case using conventional methods.