There. I said it and I'm glad!
Even after owning and maintaining a number of homes, and even after successfully operating my own handyman/remodeling service for a number of years after "retiring", I have NEVER met a caulk or a caulking job that I liked.
I somehow overlooked this minor character flaw in myself as I undertook this project. Add to this the fact that I now have all (three on a good day) of you looking over my shoulder and following my progress. There is no manly way out of this but to persevere and complete the task of "gluing" the cans together to form the collector tubes.
Given the number of joints involved, perhaps by the end of this process a technique will develop. I did observe that by the time I had done three of the tubes (36 cans) today that my technique and comfort level had improved.
I began by applying a small bead of white silicone caulk around the outside of the bottom dimple of a can.
Then, with a wet left index finger, I smoothed the bead of caulk at the joint while I rotated the assembly gingerly with my right hand.
Be careful to insure that you have complete coverage to prevent any air leaks later.
I used a couple of different fixtures to keep the cans aligned during the curing process. The one shown here is simply two scrap pieces of 3/4" plywood glued and stapled together to form a trough.
I'll post more photos of this process if there happen to be any breakthrough techniques to share, but I expect the next post will document the frame-building process.
Thanks for looking.