Cracked Flue

[davidL]

I fired up my oven for the first time to full temperature (+700 degrees F) and the horizontal flue cracked. The horizontal flue is made out of clay flue liners, as is the chimney stack, and it cracked where a smaller horizontal piece is sandwiched in between a 2' section and the chimney stack. The horizontal pieces had one side cut off and placed so as to form an upside U to form a channel. Temperature readings on the flue during firing never exceeded 325 F. The oven went to over 725 in places. I think the biggest cause for the crack was a mortar joint a little too large caused by a not quite flush fit.
I need to get this fixed, obviously. Should I; A, Fill crack with more mortar and continue firing. B, Repair the crack with a thick glob of castable refractory cement, C, Can I pour and encase the clay liner in a refractory cement or D, remove the horizontal pieces and create a whole new horizontal flue with castable?
Any help, or sympathy, is greatly appreciated

[brickie in oz]

Id encase it with refractory concrete.

Have you got any more pics of your oven, Im interested to see the design having a horizontal flue and all?

[Les]

Originally Posted by brickie in oz

Im interested to see the design having a horizontal flue and all?

No doubt. the gasses from the oven want to go vertical, or at least mine do

[davidL]

I'll post some more up. It's a lot like Doug Spaldings' design with a few tweaks because of lack of blocks in southwest US. Encasing it right now, I'll let you know how it went