Nate Cougill

Yes, exactly! The sheet metal has no strength to resist a bend otherwise. You'll notice this on HVAC ducting and other things. Once you start looking for it, it's everywhere ;)

I am not familiar with araldite, but you could do a grooved flat lock seam and silicone it from the inside. If you're trying to make the keel joint where the two hulls meet, you may be able to form this from a single sheet rather than seaming it. Forming By Raising: Heat it to anneal the sheet. Use a blunt v-shaped die over a wooden form or sandbag to begin to stretch a ridge in the sheet. Anneal often. Use a ball peen hammer and work out from the keel and up the hulls and raise the radius into the sides. Trim flush with a pair of snips and clean up on a disc sander. Copper would work best, and you'll want the sheet to be a little thicker than your finished piece. Rotary Seaming:You could roll a hem on a rotary machine. That's how soda cans are made (kind of) and they're water tight. Bo...

I am not familiar with araldite, but you could do a grooved flat lock seam and silicone it from the inside. If you're trying to make the keel joint where the two hulls meet, you may be able to form this from a single sheet rather than seaming it. Forming By Raising: Heat it to anneal the sheet. Use a blunt v-shaped die over a wooden form or sandbag to begin to stretch a ridge in the sheet. Anneal often. Use a ball peen hammer and work out from the keel and up the hulls and raise the radius into the sides. Trim flush with a pair of snips and clean up on a disc sander. Copper would work best, and you'll want the sheet to be a little thicker than your finished piece. Rotary Seaming:You could roll a hem on a rotary machine. That's how soda cans are made (kind of) and they're water tight. Box Break:You could also form a keel seem from a 90-120 degree bend on a sheet break. Draw the arc you want for the hull, transfer it to both sides, Cut away the excess on one side, cut away all but a 1/4" tab on the other side, then epoxy the tab to the opposite side. Silicone the inside. That said, you could also just learn to solder. It's way easier than forming sheet stock manually like this. Happy tinkering!