I've made a couple of "pepsi-can" alcohol stoves. Most of the plans have the seam between the outside pieces too low. If it leaks, you will either have burning liquid alcohol running out of the stove (bad) or burning alcohol vapor coming out (not dangerous, but it can make the stove harder to "turn off")

I like to cut the lower piece to the full height of the stove, and squeeze the upper piece inside, then seal it.

I've used epoxy and it works fine until the stove burns low, then it starts to burn off and smoke. I will try JB Weld, but I think I will rough up the can with sandpaper first, to give it a better grip.