I posted this first under general welding. This will be my first attemp at building an aluminum gas tank for my boat in well over a decade. The last time, I had access to a brake and friend tig it all up for me. I have already procured marine grade (6000 # grade) sheet aluminum. I plan on cutting to shape for my sides, bottom, top, baffels and angle aluminum. I will use angle for inside support for baffles and seams to make them super strong. I plan on using my spool gun to fasten and weld all inside. This will quickly stich everything together and provide extra strength where leaking in not a concern. Of course I will make holes for gas to flow, just not as quickly as not having baffles at all. Then, I will tig outside where seems are welded inside via spool gun. HOPEFULLY, Tig will mostly remove impurities (leaks) and provide flow. If anyone sees a problem with my technique, please offer recommendation.