I just found your post so your probably done by now. The "IRIS" is my all time favorite rocket by far! I built a 3" using all LOC parts and based my measurements off the LOC/YANK data in "Rocksim" back in 2007.
I used 30min "Devcon" for the whole build with the most of it on the inner tubes. With just very small fillets on the outer airframe. I soaked each end of all the tubes with thin CA and filled the outside spirals with Elmer's "Fill-n-Finish" and primed it with auto primer. It turned out great! And maybe one day I'll put paint on it and the custom decals from "Excelsior Rocketry" I ordered! LOL
In fact I got my Level 2 on this rocket with an AT-J350 at Southern Thunder that year. And it was begging for more motor! Here is a video if your interested...
Borrow a camera and get us a few pics! I never get tired of looking at an IRIS!