I built a wood boat once just to see if I could do it and still have it but not a aluminum one. I would think it would really not be a lots of difference and welding it would be a lots better as to being water proof. Here is a book on how to build a aluminum boat and this web site may have a plan that you may like.
Boatbuilding with Aluminum-Second Edition-boatdesign
Aluminum Construction-boatdesign
Here is a picture of the wood boat I built.