Finally Started in Southbury Ct.

[Aegis]

Re: Finally Started in Southbury Ct.

Hi Tony, I have 4" of foamglas for under the hearth. Is that the insulation you are asking about? Basically I have 42" sono tubes for footings, under the slab is 10" of 3/4 stone compacted with a sheet of plastic over it, rebar and then 6" of poured concrete. The blocks were dry stacked and filled with rebar and concrete, Then the top was cement board, rebar and 4" of concrete. That is as far as I have gotten. Next steps are 4" foamglas, hearth bricks and dome.
Come over anytime and shovel out the oven and you can see it! LOL

[Pisani]

Re: Finally Started in Southbury Ct.

Hey John,
What did you do for the floor insulation in the floor?
Tony

[Aegis]

Re: Finally Started in Southbury Ct.

Thanks for the info, it is a huge help! I am going to build a 40" oven and hoping to make pizzas the first night and then bake bread the next morning. It looks like I need to add thermal mass to the standard Pompeii design. I am prepared to heavily insulate it. 4" foamglas under the hearth, 3" thermal blanket on the dome with loose vermiculite on top of the dome. Now I just need to decide how much thermal mass and where to add it. I was thinking the hearth bricks could either be a double layer or just layed on edge. Then the mass increase around the dome???? add some refactory cement??? anyone with suggestions???
Thanks in advance

[DimTex]

Re: Finally Started in Southbury Ct.

I work with a lot of engineers so I get it. Batch of 15 loaves? That is a lot of dough. For my 36 inch Pompeii in Texas that I built with my son last year the first thing is to learn how to build the right fire. I must admit I started too timidly putting in 2-4 logs and then waiting forever never getting hot enough. then I watched a YouTube from the Forno Bravo site and I realized I was not using enough wood. Now I have a system using six logs and kindling.

Anyway once you build the fire, I found it takes more than an hour to get the ceiling of the oven white which means the fire is hot enough to burn off the soot created during the low temperature start up. Problem is I think once the oven reaches 900+ degrees in my mind the consumption rate of the logs in the oven accelerates. You don't want to feed more wood because it takes up floor space that you need for cooking.

Now you have your oven hot, white ceiling hot. You push the coals to the side, let the center floor settle (cool down slightly) and you start cooking. I think most of the charts have shown the drop off in temperatures happens fairly fast. First hour really hot, second hour maybe 30 percent lower and by the third hour another maybe a couple of hundred degrees cooler, not much. So maybe at the start of the second hour after you brush the coals to the sides you could maybe start baking. I say this because in baking a steady temp is really important. With a pie you can pull it in and out to your hearts delight, with bread you have not a clue what is going on inside. I have charred rolls with almost dough at the core. By this time, if you have a party your guests will wonder whether you will join them!

You mention days, my experience is that by about hour 5 after the burn the oven floor and walls may be hot but not bread baking hot. I have just had a metal door constructed so maybe I will be able to conserve more heat, but for now I would say I do pizza in the first hour or so after the burn, then I do rolls and then breads....

Hope this helps

[Aegis]

Re: Finally Started in Southbury Ct.

First, let me say I am an electrical engineer by day. That will probably answer most peoples questions why I do things! LOL As for the particular question, why thermocouples? I am not good at winging it so to speak. Others like yourself and my wife are really good at it. My wife doesn't understand why I use a level, she just puts up the shelf, eyeballs it a voila! Perfectly level! (I know it is level, cause when she isn't around I pull out that dastardly tool and check.. Me on the other hand, I need empirical data to support what I am trying to accomplish. I am trying to learn how much wood burning it will take to saturate the entire thermal mass. Then I want to record the cool down over days so I can have a cooking strategy that will work. Even if that means a re-fire (which I have to monitor with those darn thermocouples) I am hoping once I learn how my oven is working, then the thermocouples will be for showing guests how dam hot the oven is and not to stick their head inside! I am hoping to bake at least one batch of bread after a pizza party. Maybe 15 loaves or so... is that realistic with a straight pompeii designed oven? Or should I be looking at more thermal mass? Thanks in advance for any and all help!

[DimTex]

Re: Finally Started in Southbury Ct.

Why thermocouples? I built my 36 oven about 18 months ago and I use a infrared thermometer but to candid I hardly use it at all. I do the burn, when the dome turns from black to white I know its hot enough. I push all the logs and coals to the side, wait about 20 minutes for the center of the floor to stabilize (temperature wise) and start putting in the pies. Some folks throw in flour to see how fast it turns black, so far I just eyeball it. The heat is so high pies finish in a few minutes, bread and rolls I do near the doorway.

[Aegis]

Re: Finally Started in Southbury Ct.

Updated Oven Blogs
June http://pulse.yahoo.com/_FCBDQW43KUTX...listPage=index

July http://pulse.yahoo.com/_FCBDQW43KUTX...listPage=index

August http://pulse.yahoo.com/_FCBDQW43KUTX...listPage=index

Sept. http://pulse.yahoo.com/_FCBDQW43KUTX...listPage=index

Oct. http://pulse.yahoo.com/_FCBDQW43KUTX...listPage=index

Nov. http://pulse.yahoo.com/_FCBDQW43KUTX...listPage=index

Dec. http://pulse.yahoo.com/_FCBDQW43KUTX...listPage=index

[Aegis]

Re: Finally Started in Southbury Ct.

Not quite sure if I have too much thermal mass, It takes about 4 thousand gigga watts to heat up for pizza!

[KraemerBAC]

Re: Finally Started in Southbury Ct.

Awesome...I love the design!!!

[Aegis]

Re: Finally Started in Southbury Ct.

I'm about to electrify my brick oven and get it ready for the first Pizza! This maybe a bit different from the traditional wood fired ovens, but I am hungry and want PIZZA! I am not sure how to finish the bottom stand area to make it look a little more to scale with the size of my oven, any suggestions?

[Aegis]

Re: Finally Started in Southbury Ct.

Without the experience, I thought the trade off of splits under would be better than the extra lines that the side laying would give. Any comments would be greatly appreciated. I am also not sure if the extra mass in the floor is needed or worth it!
Thanks
John

[fxpose]

Re: Finally Started in Southbury Ct.

I am considering laying firebrick spilts and then regular size firebricks on top of those for the hearth. I am not sure if the extra mass will be needed for bread or not. I will be looking to do both pizza and bread in the oven. It seems to me the walls are 4" thick and to have an even heat soak the hearth would need to be four inches also.

How about laying the firebrick on its side like they do in bread ovens......that'll give you the thickness/thermal mass you're looking for.

[Aegis]

Re: Finally Started in Southbury Ct.

Thanks Scott and dmun, I have dry stacked the stand and it is extremely level. This was mostly due to my friend who floated the slab nicely. I did quickly find out about the 15 1/2 inch blocks when I took a final measurement of the stand. It helped me with the vertical dimension, since I will be using 4" foamglas under the hearth and I am considering laying firebrick spilts and then regular size firebricks on top of those for the hearth. I am not sure if the extra mass will be needed for bread or not. I will be looking to do both pizza and bread in the oven. It seems to me the walls are 4" thick and to have an even heat soak the hearth would need to be four inches also. I do realize heat travels up and the hearth would normally be cooler, which would compound the bread baking problem. Bread likes a hot bottom for spring/rise, although a brick oven might do that oven spring from all directions, not just bottoms up so to speak. Hmmmm did someone say bottoms up, I'll drink to that!
Thanks for the input on the ash drop, I will be doing bread so I guess I will need to figure out a good form to use for the pour. I will no doubt change my mind a couple of times before I have to commit. It not only will help/hinder the pizza/baking process. But it is also a front facade change, for either using the bottom for wood storage, or ash containment/removal.
And two thermocouples it will be in the dome.
Again MANY thanks for your input!
John

[dmun]

Re: Finally Started in Southbury Ct.

16" blocks aren't 16 inches.

None of them are. They are half an inch off in each dimension to make room for mortar joints and still have their nominal dimensions. If you've never laid block before, you don't want to start now. For something that's so commonly done, it's amazingly difficult to get the mortar to perch on the edge of those hollow blocks. The plans call for dry stacking and filling for a reason.

do I have to mortar the first course for lateral structural support or is it just for leveling? If leveling is the ONLY concern then I may be good to go. I'll post some pics after the dry stack is done.

nope, unless you are in an earthquake zone you don't need to mortar the bottom row of blocks except to level it.

where to position thermocouples?

About the only use for thermocouples is to measure the heat saturation of the dome, to get repeatable results in bread baking. If pizza is your main goal, then you almost certainly don't need them. If you are a maniac for bread baking, I'd put one (actually two, in case one fails) at the top of the dome, about half way in. That way you'll know if your dome has the same amount of stored heat, hot weather or cold, raging fire or slower one. I can't imagine any use for a thermocouple in the floor. Heat always rises.

And an ash drop needs to be under the flue or outside of the flue area?

Again, an ash drop is a bread thing. If you are daily shoveling out live fires to prepare for bread baking, you may want to consider expending the effort and space for an ash drop. If pizza is your primary goal, you'll only have a little bit of ash to shovel out the next day, or before your next bake.

[Millstone Man]

Re: Finally Started in Southbury Ct.

John - You do not need to mortar your blocks. Just but rebar in the cores when you fill them with concrete. I have not finished my oven yet but opted to omit the ash drop after reading through this website. Most seem to say it's not worth the effort. You might do a search on ash drops and read what others have said. The same for the thermocouples. The FB plans are really good. - Scott