RoyJ wrote:
Weld nuts:
http://www.on-b.com/doc/onb-nut.htm
All sorts of flavors but they do a nice job of adding threaded holes and
studs to sheet metal types of assemblies. The projections on the weld
nut provide a focal point for the heating.

Those are neat, they could be handy, except ...

Typical weld heat requirements here
http://www.on-b.com/weld/wd-lc-nu.htm

20kva minimum!

Although I don't see how it would be much harder than the 2 1/8" pieces
I welded together.

Bob