I just won a Hoffman 20*20*8 enclosure on eBay, but it does not have a back plate to mount stuff on. My question is can I get a piece of plexy glass and mount that? Does it have to be metal? Thanks in advance
I think it needs to be metal plate. Things can get hot when components malfunction and plastic will not hold everything in place and its also going to catch fire.
You should be able to get a piece of sheet steel or aluminum from a metals supplier locally. 1/16" for steel or 1/8" for Aluminum should be OK.