I'm a first time boat builder who has tried to learn as much as possible about the process of constructing an aluminum boat. My boat is a 28 footer made of marine aluminum. I worked with Bill Lincoln (great guy, wonderful architect) and had my dream boat water jet cut from marine aluminum at Pierce aluminum. The building process has been going well (all the frames have been welded and are ready to install). Yesterday I misread the welding schedule for the two main girders/stringers which support the stern of the boat. Basically they are 16 feet long, 18" wide of 3/16" aluminum capped with a 1 1/2" x 3/16" flange on top. Each girder has 4 slots cut in it to receive the frames which intersect it. I should have known better but when I attached the flange the welds contracted enough to bend the girder approximately 5/8" along the top of the flange. In the attached picture you can see the straight girder placed on top of the bent girder to get an idea of the deflection. This may not sound like a lot but these girders define the sole for the boat and I'd like them perfectly flat. So here is my problem, I'd like any good advice you can provide to help me straighten the girder. So far, I've tried flame straightening, and mechanical means to bend the girder back straight but it refuses to yield, even a little. A boat builder suggested cutting the girder at the slots and rewelding it in the straight position. I'd be curious to hear anyone who has had to deal with a situation like this and how they corrected it. Thanks in advance,
Bob
Bob
