UDS no weld fire box
a few seconds ago
Well I'm not a weld and don't aspire to be, that said here's what I did. 18" weber grate, 3-12"x24" 1/2 expanded metal sheets, old pizza pan as an ash collected, several nuts, bolts, washers, and most importantly cable clamps (Crosby Clamps).
Spend less than $60 and completed it in under 1.5hrs. Now before you go critiquing remember this is function over form, doesn't need to be pretty to cook some damn good BBQ.
Ideally having a form to bend the expanded metal around before installing the clamps.