3M Aerospace and Aircraft Maintenance Division 3M™ Scotch-Weld™ Core Splice Adhesive EC-3500 Part B

3M,Ñ¢ Scotch-Weld,Ñ¢ Core Splice Adhesive EC-3500 B/A is a two-part adhesive specifically formulated for core splicing applications, particularly in aerospace contexts. It operates effectively within a temperature range of -67°F to 350°F (-55°C to 177°C) and features low density and long worklife. The adhesive exhibits minimal volatile loss during the curing process, with less than 1% loss at 350°F (177°C) after one hour. The adhesive is a modified epoxy paste with a nominal weight of 40 lbs./cu. ft. and is designed to provide strong mechanical properties. Compressive strength ranges from 6000 psi at 75°F (24°C) to between 6000-9000 psi at 350°F (177°C). Shear strength is measured at 1000 psi at both 75°F (24°C) and 270°F (132°C), and 800 psi at 350°F (177°C). Core shear strength is approximately 930 psi at -67°F (-55°C) and 925 psi at 75°F (24°C). Proper surface preparation and application techniques are critical for achieving optimal bond strength. The adhesive requires a specific cure cycle, ideally at 350°F (177°C) for one hour, to attain the reported mechanical properties. Storage recommendations suggest keeping the unmixed adhesive at 40°F (4°C) to maintain its performance characteristics.