Yes my original plan was to make a "set on top" aluminum tank that was shaped to the wing... I think I saw it somewhere on here years ago (the end of my 5th video shows a picture of the aluminum tank they had started, but I think this pix may show it best...) I added an extra support on that wing too... but then I started thinking about folding the wing... I still think it best to have the tank attached to both spar for folding, but then again would probably need to be drained before folding, so I don't know if it'd matter... I'll shut up now... lol