Chimney configuration questions

[Amusinglisa]

I have some great double walled pipe (left from a construction job) -- can I use it for my chimney (photo below)? We are going for a 39" oven.

We kinda got the base a bit closer than we thought to the existing pergola (with plastic end caps, of course) and probably need to put some sort of a bend in the chimney. Any suggestions?

[Gulf]

Amus,

Do you know what metal(s) the pipe is made from? Do you know for what purpose was it's origional intended use? The outer wall appears to be stainless steel. But, the inner wall appears to have some rust. It may be dirt that I'm seeing. If the inner wall is not ss, it will probably rust out on you very soon. It is difficult to tell fhe actual ID from the angle of the pic. From the pic, it appears to be about a 7" ID (though that is an odd number). I can't remember what size oven you settled on.

[Amusinglisa]

Looking at a 39" cooking chamber. I am not positive this is a chimney sort of pipe. I will have to have someone take a look. It is possible that it is a sun tunnel... =)