Friend wants me to build him a light duty security door which will allow him to prop the main door to an underground building open so as to allow increased air flow but which exclude unwanted visitors. I guess that he envisages something like a tennis court gate but with expanded sheet steel in place of the chain link netting.
So, to the questions. Assuming that I make the frame and door from RSA steel, how do ensure that everything stays flat and square as I weld it up? Do I need more/fewer/different braces? How do I attach hinges and locks? Any pointers to plans/instuctions on the web would be much appreciated.