Hearth slab is hot -- need some advice.

[gastagg]

I have completed the curing fires. The underneath of my hearth slab is hot. I can keep my hand on it, but it seems hotter than it should be. I've got 2" of what I thought was calcium silicate, but it seems to me that it's getting too hot. Is only hot directly under the oven. Interestingly enough, due to how I built it, I could actually pull out the floor bricks, put another 1" of insulation board underneath my floor, and replace the floor without too much hassle. I'd have to build up the landing by an 1" too. My door opening to dome height ratio would go to 61%. As I'm tired of working on this oven this year, I would wait until next year.

[william]

It might be possible that your cal sil board still has some moisture in it, that would facilitate the heat transfer to your slab. might want to see how that changes as you use your oven over a period of time

[gastagg]

Hadn't thought of that. Will see how the fires go through the fall. Thanks William!

[gastagg]

William, that was the problem. I remembered today that I had not cut out the 2 layers of plastic underneath the hearth slab that I had put there to keep moisture in during the cure...in June. I looked underneath there this afternoon and there was a huge bubble of water. I cut a slice into the plastic and about a pint of water poured out. I cut out all the plastic and fired up the oven. Got it hotter than any so far...600degrees on the floor...and the bottom of the hearth slab was cool to the touch...barely any heat at all! Thank you!

[RandyJ]

They say that it will just keep getting hotter as it all finishes curing. I know that I can get to 775 F on the floor maby 800 if I look at the right spot and my thermometer only goes to 1022Fand I have seen it read Hi so I don't know just how hot it is. What I do know is it is very hard to get the readings as it is so hot in the entry you can't put your hand in to it. Good luck and keep up the good work.

Randy

[gastagg]

Thanks Randy. I bought a couple high-temp oven thermometers...one specifically for wood ovens. I hope to see those temps keep getting higher. I need to sustain a fire at 700-800...I haven't done that yet. Just gotten up there and then let cool.

[gastagg]

I think there's still a lot of water in the slab

[UtahBeehiver]

Just takes time for the water to work its way out. Each firing the oven will perform better.

[MeBeMarc3]

I think there's still a lot of water in the slab

I think that mine got saturated during my build too. Let me know how things progress.
Thanks,
Marc

[RandyJ]

I can understand your being a little cautious on the firing. I know I was for sure too. But you also have the stucco dome to worry about. When I did mine I just did a very slow long fire getting up to 7-800 degrees after 8 hrs or so. Just keep after it I am sure you will be there in no time.

Randy

[RandyJ]

Oh also I don't think I would put that thermometer in the oven when you are trying to get to pizza temps. I am afraid you will melt it. I know that when you have a dome temp of 1000 degrees you might have a air temp well above that. You might think you won't get there but I know you will. I would bet that it would work great for bread or roasting though.

Randy

[DavidApp]

I picked up a pizza oven thermometer for a few dollars. I use it as a guide when my oven is cooling. At Pizza temperatures I use an IR thermometer.

[gastagg]

ok, going to shoot for a long, hot fire today....thanks for the encouragement Randy!

[Gulf]

Russell,
I think somebody is fixin to "smell that smell" . Good luck George, and break out the bubbly .

[UtahBeehiver]

Yerp, there is definitely a smell when the dome clears...........I am sure they are laughing at us Gulf.