Workers in several specialty metal shops scratched their heads when I explained the type of hatch I need for the VLF radio-blocking unit for the Deming Box experiment. There seems to be nothing that’s widely commercially available. Please do let me know if you can find such an access door. It needs to be 18 gauge mild steel (or thicker), 24 inches by 24 inches, and have handles on both sides of the door. There needs to be full metal on metal contact everywhere. Fire rating is irrelevant.
I wonder if any readers here with technical experience might comment on the possibility of cutting an access hole of sufficient size, and then making the box radio-tight by laying a flat piece of steel – larger than the hole – on top of the hole and pressing it down with a few kilograms of weights. The solution seems a bit “Flintstonish”, but would it work?
I’m open to hearing suggestions on this.