32 Inch Pompeii in Northern California

[SableSprings]

Re: 32 Inch Pompeii in Northern California

Here's a couple of photos of my chimney transition area after a bake. The minor soot/creosote buildup I normally have after a firing is concentrated in areas where I don't get good, smooth airflow out of the oven and into the chimney. This is why I'm a bit concerned about your oven exit/chimney entrance gap & "arch dam". Yes, the soot does burn off inside the oven, but as you can see it doesn't clear very far outside of the oven's main chamber.

I know you want to finish and start the curing fires, but you'll get a lot of soot/creosote buildup during the initial firings...which will make cleaning and "fixing" this area much more difficult (and dirty work!). Again, while you've got home brew made up - use it with some fire brick scraps to fill/pack and smooth this transition area.

FYI: These pics were taken (Sunday) after my bread baking session on Friday. I normally fire the oven Thursday night late and at 7 or 8am Friday morning bring the oven up (from its overnight 400-450F range) to 650-700F when the dome clears. I make sure I've got clearing all the way to the floor and then clean out all the ash/coals. The firing door is left slightly open until I get into the low 600s when I close it to equalize. Door's usually closed from noon until 2:30-3pm when I start the bake. The first two pics are my chimney transition area so you can see the soot/smutz buildup. In the third picture you can see a portion of my cleared dome (note that I did not clean up brickwork mortar, only smoothed it) and the upper right side door opening/angle iron frame at the oven exit. The last picture is to show you some of the crap that falls down on top of my firing door.

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Seventh Course done. Unfortunately this essentially happened before I read Mike's reply so I can no longer easily access the dome-to-arch transition to try and make it smoother. I will attempt to address this later from the front.

It's probably difficult to see from the picture, but there is only a circular gap of about 10-11 inches remaining. I think this means two more (small) courses followed by a center plug.

I have a couple of weird bumps which I think occurred because I didn't use small enough bricks for the last two rows. But my interior mortar joints are still acceptably small (for me at least!) and so I will make any necessary adjustments on the next course.

I think I will attempt to close the dome tomorrow!

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Thanks again Mike,

that is great insight on the gap... thanks so much for sharing your experiences.

Unfortunately I had already almost completed the seventh course when I read your reply. Which means that I think the window for an "easy fix" has passed. I can no longer easily access the arch from the inside of the dome in order to grind it down.

So, what to do?

I can access the gap from the front of the dome - so I can still fill the gap with firebrick and mortar from the front.

I think I am going to do the following:
Complete the dome, and then start curing the oven with test fires. I think that this will give me a sense of how much of a problem I will have with this transition? Does that make sense? Then I can decide how aggressively I want to tackle the problem?

With regards to "soot" - stupid question - but won't the soot burn off when the oven reaches a proper operating temperature?

Neil

[SableSprings]

Re: 32 Inch Pompeii in Northern California

I had similar, smaller gaps on the upper sides of the dome/entry arch join. I chose to fill them with refractory mortar and chunks of leftover firebrick. After 3 1/2 years of use, the patch/plugs are still intact. One of the things I've noticed on my oven is that the heat and flame during firing come out of the oven curving pretty quickly up. I now wished I'd built a more curved path up and out into the flue. I think this heat/flame path might be more of an issue for you down the road with the gap.

It doesn't look like you can grind out the gap totally, but you could grind it down significantly so the gap and arch lip are reduced and the hot gas/flame flow out & up along a more curved path to the flue instead of hitting the arch lip dead on. I'd also think about using a little firebrick & refractory mortar fill to minimize the transition bump & gap. As a side note, I get creosote build-up in a couple dead spots I have in my chimney entry area sides (from the oven to the flue) and I find it can drop "chunks" on my landing when I least expect it. I suspect the gap you have now will fill with "crap" if you don't fill it and/or grind it out a bit...and although it won't probably affect your oven's performance "black s---" is going to drop on your food and/or turbulence will put more smoke out into the room than you'd like during firing. Easier to address it now...

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Sixth course done and I finally have a circle! (or at least as close as I am going to get to a circle!)

The dome-arch transition was a bit of a PITA as I suspected - and it is not nearly as elegant as most here on this forum.

One question, because of the way I did the transition I do have a gap behind the arch and in front of the dome. It is only about 1 1/2 inches high. I guess smoke and heat could collect there? I tried to take a photograph to show this - see attached. Is this anything I should be concerned about? It is completely sealed and at all points there is always at least 2 inches of brick between the interior and exterior of the oven - but if necessary I could try and fill the gap with mortar. I am hoping it is no big deal.

Neil

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Thanks so much for the feedback, Mike!

Yes, I have been a little concerned about the weight of the chimney and the arch buttressing. I do want it to have a brick surround but i realized that I think I can support the brickwork on the foundation and not necessarily on the oven arch. I have ordered a 6" DuraVent flange and chimney sections which I will place inside the outer brickwork. (I think 6" is big enough for a 32" oven). I don't think those weigh much and then I only have to support the chimney "box" (which will be made out of bricks) on the arch.

Good input on the brick joints! Yes, they have been getting too close so on this next course I was more liberal with 1/4 bricks where necessary to get the alignment back.

Neil

[SableSprings]

Re: 32 Inch Pompeii in Northern California

I'm impressed how fast (and nicely) your build is coming together. I did notice on your last pics that more and more of your course brick joints are lining up...try to keep those alignments to a minimum to reduce "crack potential" in the dome for the remaining courses.

I don't know if you've decided on the brick chimney or not at this point. I do think if you add the "heavier style" chimney you will want to beef up the buttress mass/support for the entry/chimney arches...remember that a lot of weight will be pushed out to the sides from above. I don't think that what you have now will be enough for a brick chimney...and I'd tie those extra support buttresses down to the slab on each side if possible.

Fabulous looking setup! Looking like you'll be able to develop your pizza skills in plenty of time for the Fourth of July.

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Thanks KB! I might try and close the dome this weekend - depending on how much time I have to work on it.


You must be almost closed yourself? Or maybe already done? I think the last picture you posted was course 6 or 7.

Hope it's going well!
Neil

[kbartman]

Re: 32 Inch Pompeii in Northern California

Looking good Neil.......!!!!!!!!!!!!!!

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Fifth course done. I also placed the first flat course of bricks on top of the inner arch. I will start to build the back part of the chimney on top of this. (but will build the outer arch before I get too far with the chimney). I also angled these bricks at the back to tie into the dome.

[UtahBeehiver]

Re: 32 Inch Pompeii in Northern California

I ended up doing a full arch versa a partial arch with my thought being minimizing outward thrust. I also did not have a heavy brick chimney above my arch. No crack or shifting as of yet.

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Thanks Russell!

well your arch is almost perfect - and you certainly have set the standard for arch to dome transitions!

Question for you - early in your thread you said you you most likely going to buttress your outer arch - but then I see from your later pictures that you didn't do that.

Were you worried about the arch pushing out at the bottom? Have you seen any cracks?

Cheers!
Neil

[UtahBeehiver]

Re: 32 Inch Pompeii in Northern California

Lookin good, almost clearing the arch. I don't think there are any perfectly cut ovens out there, well maybe Les's

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

I completed the inner arch. Not perfect, but it is structurally solid and only the lower inch of the arch (for the reveal) will be visible. Also, it seems that the inner arches get pretty black very quickly!

I am pleased with the amount of buttressing between the inner arch and the dome. I think there is plenty at the back to prevent collapsing.

When I get to building the arch that supports the chimney I may use some metal brackets to buttress the arch that covers the landing.

Next step is to tie the dome and inner arch together! Lots of brick cutting ahead!

Neil

[boerwarrior]

Re: 32 Inch Pompeii in Northern California

Wow, Les, I just took a look a your build - it is incredible!

Your brickwork is amazing - how did you get such clean lines?

I am using the "antique" style bricks which are pretty forgiving in terms of lines and accuracy. I wouldn't dare try and use tight clean joints like yours until I had way more experience!

Your kind comments on my build are much appreciated!

Neil