I made a hard wood framed biscuit jointed,glued and screwed together. then glued and screwd 1/2" plywood to that. stained the bottom then went over the whole thing with waterproofing stain. I glued and stapled around the edges of the canvas. I then laid a bead of caulking all the way around the edges of the canvas. I made the outside frame out of 22 gauge primered sheet metal at work bent it to look like a J painted it with hammered black rustoleum and pushed it over the caulk canvas an frame.