I am trying to weld a mild steel 3" x 3" x 0.25" square tube with a flat plate measuring 5" x 5" x 0.25" (the flat plate must weld to the end of the square tube and be perpendicular to each other--this is for the gantry that will stand vertically). Think of the square tube as the gantry and the flat plate as the base that will be bolted to the floor. What are the various ways to hold the flat plate to the end of the square tube so that I may weld it and have it line up squarely? What is the best way? Since the square tube was not cut squarely, I cannot simply hold the flat plate flushed to the end of the square tube. I have the welders magnetic squares, but the holding power is too small and the larger squares cannot fit with the small plate. |