It will make good smoke and steam stack, but 22 ga is most often used for pans. It would be harder to weld , and a formed heat sink at corners would be necessary I would think.
I'm not sure on the finish, I know many use a dull finish on budget pans because mirror finish costs more.
I guess the pan sizes might make a difference as far as the strength of the finished pans, what size pans are in your plans?
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.