Chimney for cast oven

[sriceky]

I am moving forward on the planning stages for my cast oven - spent a couple of hours on CAD this weekend laying everything out. One area that I am looking for advice is my chimney. I notice that the Forno Bravo Primaveras use a clay flue pipe as the chimney and the Giardino kits use a stainless flue. I like the looks of the clay flue, but would I need to worry about the durability of the a clay flue? Should I go with a single wall stainless flue?

Cheers!
Steve

[sriceky]

I'll answer my own question. After a couple of months of usage (and before the first freeze of the winter), I noticed a long crack on my terracotta chimney. To be honest, I was more worried about the effects of this winter, but if it was going to crack, it was better sooner than later. I was able to find a suitable insulated stainless chimney pipe and crack. The OD was just slightly larger that the clay flue. It took about 40 minutes of careful work, but I was able to remove the clay and install the stainless flue with minimal damage to the stucco on my oven. It did take a little "machining" to slightly increase the size of the opening for the stainless, but overall it wasn't too bad. Probably 15 minutes of stucco repair over 2 days and the swap was complete.

It is my opinion that you shouldn't waste your time and effort with a terracotta chimney. Pay the few extra $$ for stainless at the beginning and be done with it.

[david s]

Unless you insulate around a clay flue it will crack. The difference in temperature between the inside and outside is the culprit. Once insulated that difference is reduced drastically and the clay flue should remain intact, that's why they are called flue liners.