Hi, does anyone know what I can use for a form to build a barrel type oven around 27" w x 19" h x 41" L? I don't want to build one, and there is a form on the web that I can buy for 129.00 but I am trying to cut costs. I am trying to find a metal barrel but no luck so far. I was also wondering if someone can help me with what goes on top of the ceramic blanket and how many inches of it. I have first the firebrick walls, then 4 inches of cladding on top of that, then 3 inches ceramic blanket with chicken wire, but then what goes on top of that and how many inches of it? The recipe that I found on the web for cladding is: 4 parts concrete mix to 1 part portland cement to 1 part lime. Hope that's correct! Any advise would be greatly appreciated.