Adhesive studies being performed in the Thiokol Propulsion R&D laboratory by technicians for use on the Resable Solid Rocket Motors used on the Space Shuttle needed validation as to the reliability of the data being generated. In an effort to ensure that contamination, which can adversely affect adhesive Joints, was not present m the process and to verify that the technicians were properly trained in bonding operations, a certification process was initiated. Testing was started in 1992 using an epoxy adhesive used on the Space Shuttle rocket motor booster nozzles, which was is sensitive to contamination and process variation. Initial data obtained when bonding steel buttons to a steel panel in tension were erratic. A change of the adhesive storage from ambient to cold storage considerably reduced the variation obtained in the data. With this change the monthly certification process has been used to resolve contamination/adhesive issues. The results obtained to-date indicate that the variation in the overall results is essentially due to lot-to-lot variation in the adhesive rather than technician variability, contamination, or process variation.
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