Best thing to do if you need to rotate is, to pre wrap the ground cable so as you roll it to weld, it unrolls the wrap you did, no dragging that way. But its better to just do 4 welds, just make sure you tack it, weld one quarter of it, then quickly do the opposite side, so the shrinkage wont pull it out of square, then just weld the other 2 sides.