Crack after third curing fire

[briram]

Hi,
I hope you can help me with my concern.

I've finished my pompeii oven (36") a few days ago and I've started curing it with a small stack of wood for about an hour. The measured temperature was about 80 °C. I've pushed the fire a little to the back as I was worried about the dome as it was the latest building block that might have needed more time to dry.

After the third fire, I've seen a crack on the back of the oven. It is across the cement between the bricks. I didn't insulate the oven yet and I don't know whether to be happy to discover it before insulating or whether to be sad as I didn't even reached 20% of the target temperature and time...

What do you think?

[Chach]

It is has been said that it is better to insulate the dome before starting the curing fires. This gives the oven less of a chance at thermal shock and also keeps the heat from escaping the brick faster leaving you with a more uniform heat distribution especially after the fire is out. I have been told look for steam coming out of the insulation and if you see it your burning the fires to hot and need to back off a bit. Low and Slow is the game for this along with great patience. The turtle wins the race on this one I believe has been said before too. I don't think you have an issue with your crack but you will see how it progresses if any as you continue to cure. Another line said on here is all ovens have cracks if someone tells you they don't have a crack they are full of.....I think you'll be fine.


Ricky

[JRPizza]

Yep - ours cracked right down the back - even went through the center of a brick. Nothing we cook seems to mind ;-)

[briram]

Thanks Chach for your advice and kind words. I really think I was impatient and it seems to be a big failure in the beginning. I hope it will not expand anymore. I think I will wait a little with the insulation until I see the development after a few fires.

JRPizza That made my day

[UtahBeehiver]

It is too bad, we see this quite often when builders getting anxious fire too hot too fast But cracks are cracks and all ovens have them. I have seen worse and these ovens are self supporting. Insulate and move on.

We do recommend insulating before curing for all you builders out there at this stage of your build but before the final outer coating to help minimize the thermal differential.between the inside and outside of the dome.

[briram]

Thank you all for you advices and positive attitude. I wanted to come back and tell you I am done with my work and that I backed 17 Pizzas today as an opening celebration.

Best Regards from Frankfurt Germany