[jrow]

gomer950,

Not that big of a problem if I understand you correctly. Build the bottom unit with all your heating and controllers attached. Build it with a removable top. The top box would not have a bottom in it, and could just be set on the bottom box and fastened. Use angle stock on one side of the corner and flat stock on the other and just bolt the two pieces together! Where the bottom connects to the top just use flat stock and run bolts through the flat stock to bolt the top to the bottom! 3/16" wall steel stock would work great. You will have to be d$mn accurate with your construction or you will have to contend with a lot of leaks.

John