My word you have done a serious deals on those windows well done I can see how you must look high and low for bargains when your building such a huge structure. Could I as a cheeky question how many reels of welding wire have you used to date?
To remove vinyl window flanges, score on each side with a utility knife and then rock the flange back and forth. For next time! Also you can screw through the vinyl extrusion if needed for attaching. Home Depot has vinyl trim shapes like quarter round which work great around the edges when bedded in urethane caulking
On the other hand , do nor use the term ''angle-iron'' as I've told you some time ago ... First : Iron is the ore out of which various steel products are produced .. secondly : Once the ore is processed , it's called Steel ... Your ''angle-irın'' is L-shaped steel profile ..Also , cast-iron is a wrong word .. Have I made myself clear ??
Nice work on the major cost savings and for the work you did on the openings prep work. It wasn't mentioned in the video, but I hope that you put some type of sealant around the border of the windows when they were installed. If you didn't you may regret that omission down the road, especially on a steel-framed structure. There is an exceptionally superior product on the market called Lexel by Sashco that is an excellent sealant, but it also stays a little flexible and would be perfect for that type of application. I've seen it in Ace Hardware and a couple of the big box stores. It isn't the cheapest, but it's been one of the best-rated sealants on the market.
As I've said before ... you are a badass with the welder! Great find with the windows ... it keeps your creative wheels purring like a find tuned motor!
great savings on the glazing. crazy the price difference. and honestly. most windows are trimmed, or like the window area can be used to cover any small sins. Excellent work figuring out how to get what you want on a budget.