Starting new 36" build

[dvm]

Re: Starting new 36" build

Very excellent progress - and congrats on the fires - It does feel good to actually see flames - and smoke rising up the chimney. Since you have already covered you dome there is a good chance that you won't have any cracks (wink)
You are finishing strong. I have started making (and serving) pizza which is very fun - but slows the work pace.

[deejayoh]

Re: Starting new 36" build

More progress to report. Was a three-day weekend here in the states, so I got some work done, in addition to firing the oven twice!

I got the fascia board and the roof on the oven house, and the chimney all flashed. I hope that I did that correctly... tough to find really precise instructions for that process and it was the first time I have done it

Mounted all the trim and flashing around the bottom of the oven house. I wanted to have some element there to contrast with the stucco, and also it is a design taken from my house, which has that sort of baseboard trim.

I also poured the concrete that brings the landing height up to the bottom of the oven. I plan to cast a 2.5" thick concrete counter that will be placed on top of that.

I'm working on form designs for the rest of the BBQ area, hope to get that counter and the oven landing poured next weekend.

Electrician is coming on Weds to install the new breaker so that I'll have power to the kitchen area. I also picked up some mortar to mount the stone veneer. Hopefully I will have this thing done by the end of Sept...

[deejayoh]

Re: Starting new 36" build

Yea, the measurements would have to be after fire. Then the efficiency of the door would come into play. I can slow cook on the third day after fire, just wondering if I would have been able to stretch it out to four.

I haven't built my door built yet, but certainly the insulating value of the door is huge. Probably a bigger factor than the heat break.

If I was to guess (which I probably shouldn't), I think the heat break might give you 50-75 degrees higher temps on the 3rd day or something like that. I don't think it would get you a 4th day of cooking temps.

[Les]

Re: Starting new 36" build

So the real test would be the heat curve for an oven that has/doesn't have a heat break over a couple days. I don't know that heat at the exit would be a great measure - since the gasses are exiting right past the heat break.

Yea, the measurements would have to be after fire. Then the efficiency of the door would come into play. I can slow cook on the third day after fire, just wondering if I would have been able to stretch it out to four.

[dvm]

Re: Starting new 36" build

Nice to have a light in the eves and at the end of the tunnel! Looking Good!

[deejayoh]

Re: Starting new 36" build

The topic comes up often about the effectiveness of a heat break. The issue wasn't even a dream when I built my oven but I am skeptical of how much value they add. At the end of the day, fire brick are not great conductors or insulators of heat. My oven's entry does not get hot as well - I can put my hand on it when the dome has burned clean. We should document the temps from dome center, to halfway to the exit, and exit. I'm curious to see if there is a real payback for the labor (there are obvious variables that will skew the results). What does the forum think? I had no plans on firing the oven up tomorrow but I will do it for the cause.

The objective of the heat break is to help the oven retain more heat longer - have more heat into the second and third day because less is lost to the heat sink of the entryway. So the real test would be the heat curve for an oven that has/doesn't have a heat break over a couple days. I don't know that heat at the exit would be a great measure - since the gasses are exiting right past the heat break.

That said, I think the labor cost of a heat break is minimal. I don't think I would have saved any time by not including, except maybe the time I waited for my high temp caulk to be delivered since I ordered from a slow vendor.

[deejayoh]

Re: Starting new 36" build

I am starting to see the light at the end of the tunnel. Got the wiring in and the lights installed

all the sheathing on my oven house and the outdoor kitchen. Woo hoo!

I did a test fit of my cabinets and doors, and propped up some of the stone I will be using on the oven base and kitchen area to see how it will look

Check out the view from my back door! Oven pron!

[Les]

Re: Starting new 36" build

I do not find that the front arch of my entryway gets very hot, even when the oven is at full temp. Perhaps that is because I have a heat break, perhaps it's because the oven draws well and the gasses are going up the chimney.

The topic comes up often about the effectiveness of a heat break. The issue wasn't even a dream when I built my oven but I am skeptical of how much value they add. At the end of the day, fire brick are not great conductors or insulators of heat. My oven's entry does not get hot as well - I can put my hand on it when the dome has burned clean. We should document the temps from dome center, to halfway to the exit, and exit. I'm curious to see if there is a real payback for the labor (there are obvious variables that will skew the results). What does the forum think? I had no plans on firing the oven up tomorrow but I will do it for the cause.

[GianniFocaccia]

Re: Starting new 36" build

Great feedback, Dennis. You have obviously thought through many of the properties as they apply to construction and performance on your oven. Question: How hot does your SS entryway get during pizza-time, vs an hour after closing the oven up for the night vs the next morning. I think this curve is the measurement that reveals the effectivevness of the heat break.
I'm struggling with the decision of keeping my firebricks under my entryway floor (3/8" stainless plate) or going with some form of insulation. Thanks in advance.
John

[Amac]

Re: Starting new 36" build

Maybe you're right Dennis - mine gets hot - too hot to handle - and I had one crack in a mortar joint at the outer arch - but it seemed that just at the top of the arch it gets too hot to put your hand on.
Somebody else - I can't remember who (who built a round tower type enclosure?) had a similar crack which transferred out to the decorative part - so it's not really for heat retention.

[deejayoh]

Re: Starting new 36" build

I do not find that the front arch of my entryway gets very hot, even when the oven is at full temp. Perhaps that is because I have a heat break, perhaps it's because the oven draws well and the gasses are going up the chimney. What ever the case - an expansion joint seems like serious overkill for an area that probably never hits 200 degrees. I'll have to check it with the IR thermometer next time I fire the oven.

As for it be easier than a heat break at the oven, I guess that may be true - but it also seems far less useful in terms of retaining heat in the oven. A heat break between two surfaces that are exposed to open air isn't going to do much for heat retention at all.

[Amac]

Re: Starting new 36" build

It is much simpler to have this expansion joint in this position rather than between the oven and the entry structure.

Also even if you put the heat break or expansion joint between the oven and the entry - the flue gases will still heat the outer arch via the entry (and those gases are hot) - so the decorative arch will still be liable to excessive heating

[david s]

Re: Starting new 36" build

Insulating between the outer arch and the decorative arch is a good plan IMO because it will act as an expansion joint allowing free movement of the inner elements of the oven to expand without having any contact with the outer shell. The second advantage is that it reduces the temperature differential, responsible for developing cracks, on the decorative arch. A third advantage is that the decorative arch is left cool enough to touch making it safer by reducing the possibility of burns.It is much simpler to have this expansion joint in this position rather than between the oven and the entry structure.

[dvm]

Re: Starting new 36" build

dvm -
Why the rope between the outer arch and the decorative arch? It's not so hot there (assuming your flue is drawing) and you don't need to worry about insulating for heat loss as it is open to the air.

I guess I am thinking that if the flue is not drawing (windy?) I would not want smoke entering the "enclosure". I plan to take the oven to pizza temperatures tomorrow (insulation is installed), Hopefully The draw will be so amazing that no smoke dare make a break for the outer arch and this is a non-issue.

[deejayoh]

Re: Starting new 36" build

dvm -
Why the rope between the outer arch and the decorative arch? It's not so hot there (assuming your flue is drawing) and you don't need to worry about insulating for heat loss as it is open to the air.