Alodine is a chemical conversion coating. It is important to rinse after application and NOT to let it just dry on the part. This is in all the instructions for the product.
If you do not rinse, you will loose bond strength as the surface of the treated part will have remnants of evaporated alodine. Whereas a rinsed surface leaves nothing behind other then the altered surface of the aluminum which is chemically bonded.
As far as a great structural epoxy is 3M scotchweld 2216 b/a. It is the same product as EC-2216 B/A which has been labeled, packaged, tested, and certified for aircraft and aerospace applications.
This is the epoxy used by rotorway in and helicycle in the construction of their blades. It is good stuff.
http://multimedia.mmm.com/mws/mediawebserver.dyn?6666660Zjcf6lVs6EVs666GGfCOrrrrQ-
It is also availableat AC Spruce:
http://www.aircraftspruce.com/catalog/cspages/3mAdhesive2216.php