READ: i must say that the guy on the video never said it cant be done, just that it wasnt safe..... Our Unfinished underground shelter made of three 40ft shipping containers we painted the entire outside with a latex rubberized paint reinforced the inside with some woodwork  and wired it to the grid temporarily until we get our solar pannals please fill free to ask questions i would be glad to answer and help i will post more videos as our progress goes along. P.S sorry for the bad camera next video i will use a better one