Origen: 36" Pompeii Oven Build: Just getting started and have some questions....

[Origen]

And also the hardest thing I have ever done! I don't even want to cook in it...I just want to stare at it and wonder what compelled me.

[JRPizza]

Nice brick work! Start cooking in it and you will remember why you built it

[Origen]

That's very kind of you to say, but I'm not about to invite any journeymen masons over for pizza!

[RandyJ]

Awww come on why aren't you going to invite us all over for a pizza party to celebrate the finishing of the oven. From what I can see from here it looks great. You should be very proud of your oven. Congrats on getting it done. I still have a few things that I need to do. We will see if that ever gets done.

Randy

[Origen]

Thanks for the generous comments! I know what you mean: I could see tweaking this thing for at least a few more months! I don't know if this is a common thing or not, but, I'm actually thinking about building another one to correct the things I missed with this one! That's a sickness right there!

I'm in the final stages of curing--the first two courses seem to be resisting moisture release; is that "normal"? I have roasted a few things along the way--absolutely the best whole chicken I ever consumed. I can't wait to build that monster fire and cook pizza and bread.

[Gulf]

Origen,

+3 on your fine brick oven.

I'm actually thinking about building another one to correct the things I missed with this one! That's a sickness right there!

If it cooks great, then you didn't miss nuthin' .

I'm in the final stages of curing--the first two courses seem to be resisting moisture release; is that "normal"? I have roasted a few things along the way--absolutely the best whole chicken I ever consumed. I can't wait to build that monster fire and cook pizza and bread.

Hold off just a little longer on the "fire from hades" . The way an oven drafts, air is pulled across the floor. I'm sure that you have noticed when starting a fire, the level where the smoke levels off above the floor. That is a probably about the height of those first two courses you mentioned. If you are in the final stages of drying, you are producing some coals. You can drag some of them to the door to build a short levee across the opening or place one layer of brick across it. That will help the radiant heat to heat the floor without having to compete with that cool air that is being drawn across it. Getting the floor dry is key to drying the lower courses of the dome.

[gastagg]

Great oven Origen! Congrats and enjoy!

[Origen]

Thanks George and Gulf.

I figured the floor was probably the issue. I have been leaving the coals at the perimeter (and also supplementing the firewood with chunk charcoal to create more radiation), but I have not put them across the opening. I will do that and also add the bricks. I made a copper insulated door, and after the fire is burned down, and that is put in place, it holds in heat well. Hopefully, that is assisting the dryout. Each time I set a fire, it is getting to temperature and holding heat longer.

Speaking of draft: during the build, draft was one of my primary concerns since it is so important. I had no clue what I was doing, so it was haunting me until I could test and observe it. I have to see if I can capture this in a photo. When the oven chamber is filled with smoke while the fire is starting, there is a dramatically clear line about the halfway mark of the oven opening--smoke above, oxygen below. That smoke is pulled into the vent chamber and up the chimney like a jet stream--maintaining that demarcation line. The smoke never leaves the vent chamber to pour out the opening. For me, it is the coolest thing to watch.

Gulf, I sure wish I saw your method of cladding your dome before I made the bone-headed decision to use full size bricks to go around mine. That was slick, and probably put you into action quicker. And, it looks great!

George, quite a while back, I was on your build section and saw that work with the re-do of your vent/arch. Excellent recovery: a powerful display of the human spirit! Really well done!

[Gulf]

When the oven chamber is filled with smoke while the fire is starting, there is a dramatically clear line about the halfway mark of the oven opening--smoke above, oxygen below. That smoke is pulled into the vent chamber and up the chimney like a jet stream--maintaining that demarcation line. The smoke never leaves the vent chamber to pour out the opening. For me, it is the coolest thing to watch.

Just wait until that smoke finally does clear. A little later, you will look into the oven and see the dome beginning to loose it's soot at the top and feel your face becoming unusually warm. You will look at the top of the flue and notice that there is no smoke coming out?. Depending on the weather and wind conditions, you may notice an alarming creosote smell. It will be sort of an oh sht moment. But in time, that will become the smell of success. And, it will be the beginning of the real "sickness" .

[Origen]

So, over the past few days, I have been building fires in the 500-600 degree range. The bottom two rows have just about caught up to the rest of the dome. That dome is black as night--so is the vent arch and flue. Really heavy creosote build-up. I was surprised at the extent of the build-up: I have only been burning hardwood--oak, hickory, and cherry (a couple of pieces of walnut, and a little pecan). It looks like a firebox that has only burned pine, cedar and fir. Last night, at the peak of the fire, some bricks in the back of the dome turned "whiteish". This did not occur at the top of the dome. I thought the heat would be greatest at the top of the dome and that's where the clearing would first occur. Anyway, I'm thinking of building a monster fire soon. I wanted to clarify something: when the superhot fire is lit at this stage, that creosote is going to burn away right? And you're saying that generates a lot of smoke and will pour out the opening? I need to make sure my neighbors don't call the fire department so I want to get a sense of how aggressive this is. Thank you in advance for any assistance.

[JRPizza]

The last fire I built kind of got away from me and most of my "black" burned off at once, and even then it didn't look like a house fire . Most of the time (without a raging fire) the top of the dome clears first, then I push the fire to the rear and then the sides to totally clear the oven. I'd just recommend building "medium" fires till the center of the dome clears then moving the fire around. This is the method described in Forno's Wood Fired Cooking pdf, which I got from their store. You might want to pick up a copy.

[SableSprings]

I'd second JR's recommendation with the medium fire to center spot clear and then moving the coal/fire pile around to clear more of the sides during your clearing process. Not to scare you but to prepare you...you will eventually have a fire that's a little intimidating (hopefully well after the curing process ). You've built a very nice oven and it will be able to handle pretty much anything you do to it...the Pompeii design has a great track record! The creosote will burn off cleanly and you (or your neighbors) probably won't even notice when it happens...it's not really the type of chimney fire situation that exists in home fireplaces and wood stove pipes.

Just so you see that "big fires" happen to all of us occasionally...here's my latest story. I started filling my oven with wood and firing it up the night before a bread bake several years ago. I'd light it up about 10 pm, damp it down with my door so the fire was in a controlled, even burn, and by morning the dome had cleared and the fire was down to a few coals and the oven was heat saturated and ready for temp equalization. For some reason last week, I filled up the oven, but instead of putting some wood pieces criss-cross, I stacked them all fairly tight and parallel. About 20 minutes after starting the fire, I went out to make sure it was going well before I turned in for the night. What I found was that I'd choked the breathing path of the fire in the oven and it was producing lots of hot off-gassing from the rear of the logs which was igniting in spurts as it came over the top and got closer to the door (and some oxygen)...almost a back-draft situation. I had to pull the door back and open a path back into the oven so it would burn more evenly. As JR noted above, it felt like it had gotten away from me but it was nice to see the flue action working as it was designed...as someone in another thread said in response to "How big a fire do you need to prep the oven for pizza?"..."looks like the fires of hell" .

I attached a picture below of what my "fire from hell" looked like as I pulled back that door last week to clear an oxygen path. Interesting to see the flames coming out and going straight up into the flue.

[deejayoh]

I recommend reading pages 21-23 of this book: https://books.google.com/books?id=bP...page&q&f=false

Good reference material on getting your oven cleared.

[Origen]

Apologies for the delayed response...I had to go to the Desert in Cali for a little while for a family matter. I do love the Desert in autumn--really beautiful.

Thank you all for the feedback. I took a quick look at that book--that's great? Mike, that picture is very descriptive, very helpful to gauge fire size. JR, that is exactly the situation when the rear of my dome went a little white: I had a medium fire in the center, and I pushed it to the rear. I have been starting fires at the front, pushing them to the center when established, then moving them around the dome. I will continue that protocol as I build bigger fires. I'm thinking this weekend I should be able to be at pizza temps. I have cooked a lot of food during the curing process, so taking that slowly has been a pleasure!

Thank you all again for your assistance.

[david s]

Just so you see that "big fires" happen to all of us occasionally...here's my latest story. I started filling my oven with wood and firing it up the night before a bread bake several years ago. I'd light it up about 10 pm, damp it down with my door so the fire was in a controlled, even burn, and by morning the dome had cleared and the fire was down to a few coals and the oven was heat saturated and ready for temp equalization. For some reason last week, I filled up the oven, but instead of putting some wood pieces criss-cross, I stacked them all fairly tight and parallel. About 20 minutes after starting the fire, I went out to make sure it was going well before I turned in for the night. What I found was that I'd choked the breathing path of the fire in the oven and it was producing lots of hot off-gassing from the rear of the logs which was igniting in spurts as it came over the top and got closer to the door (and some oxygen)...almost a back-draft situation. I had to pull the door back and open a path back into the oven so it would burn more evenly. As JR noted above, it felt like it had gotten away from me but it was nice to see the flue action working as it was designed...as someone in another thread said in response to "How big a fire do you need to prep the oven for pizza?"..."looks like the fires of hell" .

I attached a picture below of what my "fire from hell" looked like as I pulled back that door last week to clear an oxygen path. Interesting to see the flames coming out and going straight up into the flue.

What you describe is the chamber choked with fuel. In kiln firing this is called a reducing atmosphere and can often lead to a temperature drop. I've done the same with my oven, the wood just goes black and won't burn. It's easier to do in a small oven where the volume of too much wood also reduces the volume of the combustion chamber. If you have flames going up the chimney then this is an indication that you've loaded too much fuel into the chamber. You want to get the chamber full of flames and just have them slightly licking around the top of the oven mouth. For an ideal oxidation atmosphere less is best and you get a faster temperature rise. Otherwise it's just like a car running on an over rich mixture, a waste of fuel and less than ideal combustion.