On 12/6/2022 at 9:16 AM, Duvel said:
I think this scenario is highly unlikely. The inside of the chamber will graduately heat up as the fire develops, the thermal mass of your oven will delay the process even more. Water will continously evaporate, not in an explosive fashion. If heated too fast I recognize the chance of cracking, but for a violent explosion (the "BOOM") triggered by pore-enclosed water in set-up for example as pictured above from @Margaret Pilgrim I see very little chance.
Respectfully, I don't think you're grasping the porosity of these materials. Regardless of the amount of heat applied, it takes a very long time to drive the moisture completely out of a brick. Every masonry oven kit that's sold comes with some residual moisture. This is why curing instructions are always included. It's a painstaking process that starts with small fires and takes at least 4 days Even when following the instructions to a T, cracking frequently occurs. A properly built fire (dry wood, kindling, basic understanding of how to arrange the wood) can drive the ceiling of a wood fired oven up to 1000F in as little as 20 minutes. There's not a damp brick on the planet that's going to be able to release it's moisture in that time frame.
Can I say that there's an X percentage chance a damp oven will explode? Of course not. But the Chefsteps oven that @lemniscate posted can give us a very rough idea. I haven't read the youtube comments in over a year, but, the last time I went through them, there were 4 reports of explosions. It's a very popular video, but, I guarantee you, by that time, no more than 1000 people had attempted to build it. 1 in 250 isn't what I'd call "highly unlikely.' If you look at the risk of frying a turkey, it's probably safer than that, but, it's still not something that, imo, anyone should knowingly do.
And, even if you think that's a risk you're willing to take, it's critical to understand that while an explosion isn't guaranteed, damage is. So maybe your particular oven won't explode, but, when heated damp, it absolutely will crack, and if it drops a piece of the ceiling into the pizza as it's baking, there's a really good chance, if it's small, you won't see it. As I type this, I'm running my tongue over a chipped tooth that was a result of a pebble from a pizza oven ceiling. Can you imagine the humiliation of having one of your guests chip a tooth? Yeesh. And even if THAT'S a risk your'e willing to take, a few firings with damp brick and your oven is done. Red clay bricks are cheap, but they're not that cheap. And even the barest bone setup is going to take a great deal of labor.
As I said in my previous post. I cut corners on just about everything. This isn't something where you can cut corners.
