Stop in for a cup of coffee

18 gauge steel. Wire form the opening.[/QUOT
I have no sheet metal break, or ability to weld aluminum....Might be an issue....But I still think I can make one....
All you need for a sheet metal brake is two heavy duty hinges from Home depot(4 bucks) 2 pieces of 1/4 in wall 2x2 square tubing, a piece of 1/4 think , 2 inch wide flat. Two grade 8 7/16 bolts. A drill and tap. And a welder.