So I have a project coming up this weekend, finally sourced the metal for it as well as a way to get the metal here (what a PITA that was)

Nearly 200 ft of 1/2" and 3/4" 16ga square stock will be welded up into rectangular shapes around 5'x1'. So essentially a TON of right angles.

Trying to figure out the best way to make up these boxes so I don't distort them and all corners stay at 90*. My initial thought was to cut all ends square, weld them up, then weld caps on the open ends (yes, holes drilled and a vent hole at the very bottom). That seemed like it might be a pain, so I was thinking I'd miter as many as I could. Need to either buy a corner clamp or weld up a jig, BUT, here's the question:

If I miter them, would it be better to weld from the inside corner to the outside corner on the faces, then the corners, or weld the corners then the faces, or weld from the outside to the inside? What would leave me with the least stress and best corner angles? The welds will ALL be ground and filed at the end, so appearance is less of a thing than strength and precise corners.

I do not have a table, this will be done with separate corner jigs and welded up on a concrete backer board for a table (no money for a table yet, though I know that would be the best way to lay this out).

Shape is kind of similar to this, with 3/4" square stock on the outside and 1/2" on the inside