Our design utilizes SikaFlex 552, which is designed for the transportation market. Utilizing a design rules matrix (strength, flexibility, UV safe, cure time, application time, availability, etc.), we compared adhesives in the market and found ours to be the best overall solution. 552 was formulated for this application and has superior UV resistance, flexibility, and adhesion properties. Yes, other adhesives will work, but since we provide the adhesives with the kit and this is what we recommend, it is best to use Sikaflex 552 for assembly. For finish caulking, especially if you want a different color, we also recommend Bostic brand adhesives (70-1A).
Reminder: The aluminum extrusion is also designed for this adhesive, maintaining optimal bead size for adhesive performance. Anodized aluminum promotes an amazing bond and the aluminum only needs to be clean, wiped with an alcohol wipe to remove any dust, both aiding the proper application and strength integrity.