CRACK in my arch? Firing Your Oven Discuss CRACK in my arch? in the Oven Management forums; So I cured my oven properly and then after about 5 hot fires this crack developed in my arch. Is ...

[Loafin]

So I cured my oven properly and then after about 5 hot fires this crack developed in my arch. Is there a way to repair it or should I just take my chances? Any ideas would be helpful, Thanks

[splatgirl]

Eh. Mine has a WAY bigger crack than that.
As Jay would say "bake on"

[lwood]

Don't worry about it, maybe a little heatstop or refractory mortar, to fill in the crack if it bothers you.

[texassourdough]

To paraphrase Hogan in Crocodile Dundee....

You call that a crack! I'll show you a crack!!!!!

....ovens always have differential expansion and I doubt anyone has an oven long without developing a crack of some kind.

Fire On!
Jay

[Pdiff]

Ok, I'll be the nay sayer here. Watch that you don't get a corresponding crack on the other side of the arch. That's what happened with me. I let it go and eventually the middle section was completely loose. The problem was, when I fired it would expand and the loose center section would slip slightly down. After many fires, this began to act as a wedge, slowly driving the arch and supporting opening walls out. Cracks developed in the side walls and they started to splay out. I had to rip out the whole entryway-vent structure and rebuild. I made the side walls much thicker this time and did a slow wet cure. Unfortunately,the crack has come again, but only on one side. Still, it make me nervous. If things get worse, Ill cut it out and remortor that section.

[Loafin]

Thanks for the heads up!

[david s]

I believe that cracks in the arch are due to temp differential ie hot on inside and cold on outside. This problem can be reduced enormously by simply having a small gap between the outer arch and the inner parts of the oven. It can be an air gap or filled with vermicrete.It also has the advantage of keeping the outer arch cooler and therefore safer, to touch. The heat loss through conduction is also lowered.

[Eric Pfeifer]

I think anyone who builds a brick oven needs to make inner peace with cracks, and assume that from time to time, minor repair will be necessary.

[texassourdough]

Well said Eric! Part of the good news is that after building the oven I think many/most of us have the skills necessary for those repairs!

Eat more Pie (pizza that is!)
Jay

[Neil2]

Mortar layer between arch bricks is too thick. Try for about 1/64 th of an inch or less.