I've got a hole about the size of a #2 pencil in my aluminum boat that allows it to take on water at a pretty decent rate. My "fix" was to jam a plastic grub in the hole backed with an old rivet, but that is only a temporary solution.
I'd like to find a DIY solution for patching holes in aluminum that will last a good amount of time and not cost me a ton of money. My first thought was to try some soda cans and JB weld... but I know nothing about that stuff. My second thought was to use Bondo, but I just don't know.
We used to scuff up the aluminum real rough and put a fiberglass patch on it. It would probably work even better with today's epoxies. We actually patched the oil pan from a crane engine with fiberglass!