Re: Broken rigid boom vang
I would go to the next aluminium welder and have him weld a plate over the whole section so that you can mount the vang there. Perhaps even weld the vang to the boom on the plate, if you don't need to unmount the vang on this side.
And yes, in the previous paragraph, there's an inclusive use of "him". I would even consider a woman aluminium welder, if I ever met one.