I got to do a little welding today. I welded on the perimeter rails on the front of the trailer. It is made of 1 1/2" X 1 1/2" angle iron. This was a pain in the ass to get started because the frame is not really that square. I mean it's square-ish but there's really not anything to start from as a base line. The two main I-beams that run the length of the trailer are not exactly ruler edge straight. They appear really straight but it if you look really carefully they flex side to side ever so slightly. This was throwing us off for a while but we managed to get a straight base line to work from. Now that the rails are in line, the rest of the frame and frame work will be square. You know what they say about starting with a solid foundation, well in this case it is a straight and square frame.