Went and got my generator exhaust flange welded, guy had quite a place. The welder he used isn't pictured but I guess it cost 10k and he says the prices of welders in general have gone through the roof the within the past 8 months. He tig welded it I believe with a 305 stainless rod. Considering how heavy the flange is he mentioned vibration could cause an issue. More on the crazy concrete pad and it's built for use later, I shouldn't have been complaining how long it took me to pressure wash my shop and garage pads/walk.