Help! Trying to make the best of a bad situation

[Antonio D.]

Re: Help! Trying to make the best of a bad situation

I think that splits would be ok for pizza as they would warm up faster and that there is a fire in the oven to keep the heat up. you may not have enough thermal mass for baking bread.

Tony

[dmun]

Re: Help! Trying to make the best of a bad situation

Splits for the floor? I don't know. I would worry that it wouldn't have enough thermal mass to hold heat to cook the bottom of the pizza.

Beautiful job, by the way. The reduced door height might slow you down for turkey cooking, but it should be high enough for most WFO tasks.

[Sam]

Re: Help! Trying to make the best of a bad situation

Hey Sam,
Call up Blair Building Supply in Maple Or Masons Masonry Supply in Richmond Hill.
I believe that they carry a thinner fire brick, possibly 1 1/4" or 1 1/2" thick.

Tony

Will the thinner fire brick work? I was thinking the 2" of brick would be minimum. Also, I wonder if the 1" of extra height at the door opening would make that much of a difference.

Thanks for your input.

[Sam]

Re: Help! Trying to make the best of a bad situation

It's a good looking oven at least! Looks like he put his effort into the finish work, rather than the functionality of it.

It also looks like many of the dome layers have long vertical joints running up the dome, rather than staggering. I'd be worried about cracking. (as if you need something more to worry about!) Has it been used much at high temps?

It hasn't reached high temps just yet. I figure a few more days of increased heat and by Tuesday I want to truly test it out.

[Antonio D.]

Re: Help! Trying to make the best of a bad situation

Hey Sam,
Call up Blair Building Supply in Maple Or Masons Masonry Supply in Richmond Hill.
I believe that they carry a thinner fire brick, possibly 1 1/4" or 1 1/2" thick.

Tony

[mfiore]

Re: Help! Trying to make the best of a bad situation

It's a good looking oven at least! Looks like he put his effort into the finish work, rather than the functionality of it.

It also looks like many of the dome layers have long vertical joints running up the dome, rather than staggering. I'd be worried about cracking. (as if you need something more to worry about!) Has it been used much at high temps?

[Les]

Re: Help! Trying to make the best of a bad situation

If you raise the floor 4.5 inches the opening is only going to be 11.5 inches. The interior height is not your problem. That may be tight to cook with. Anyone cooking with an opening that low?

Les...

[Sam]

Re: Help! Trying to make the best of a bad situation

OK I just got back from my dads place and took some photos. I also documented key measurements for discussion purposes.

The oven is 36" in diameter, the ceiling height (at its high point) is 27". The door opening is 20" wide with a height of 16".

I guess if I would add 2" insulation board and another layer of firebrick I would still have 23" of oven height, with a door opening height of 12". I hope this is enough :-)
On with the photos

Exterior View


Interior Dome... I am not sure why the first course of fire brick was applied vertically


Exterior of the dome... Without insulation. I will be adding an insulating blanket and vermiculite.


Dimensions of current setup

[asudavew]

Re: Help! Trying to make the best of a bad situation

I think, the 63% is the MAX that the oven door height should be in relation to the dome. It's not necessarily the ideal height.

The idea is to have a good performing oven, heat wise, and a functional oven with a large enough opening to operate it - cooking wise.

If the opening is taller than 63% of the interior dome height, then heat loss would be so great that the oven would have a hard time hitting operating temps. But I think a bit lower would be just fine, if not better.
Maybe just harder to use.

Just my 2 cents

Dave

[Wiley]

Re: Help! Trying to make the best of a bad situation

CajunKnight is on track regarding the height of interior dome to height of entrance problem caused by simply adding new insulation and firebrick to the existing floor. If one runs some numbers the problem becomes apparent.

The approximate interior dome height was given as 24", 63% of that is 15.25" so that is the design entrance height. If one adds insulation and firebrick to the floor one reduces the interior height as well as the height of the entrance. 4 to 5 inches of insulation and new firebrick was mentioned. 24 minus 4 leaves 20 inches and 63 % of that gives us a design entrance height of 12.6". Removing 4 inches from the 15.25 leaves us with an entrance of 11.25 inches which is a height of entrance to dome ratio of 56%

Anyone have any experience with an oven with such a ratio? The books all stress keeping close to the 63% ratio for proper airflow so one assumes it is important. I think we need some dimensions of the oven as it exists.

Wiley

[Frances]

Re: Help! Trying to make the best of a bad situation

Sounds as if you've got it well worked out, and whatever you do it'll improve the oven's performance.

Please let us know how it turns out (with pictures maybe?) - because I'd love to hear about it, but also as inspiration for people in a similar situation.

[Sam]

Re: Help! Trying to make the best of a bad situation

onething to keep in mind when adding board and brick to floor... is door going to be high enough? and if dome isnt covered yet would it be possible to relocated vent to arch opening?

My Dads vent is located at the arch opening. That they got right (Mavers Dad had the vent issue). As for the door opening... It should be fine...

[toddj]

Re: Help! Trying to make the best of a bad situation

Can you lift the slab/oven off the stand with a forklift, then pour a new concrete slab, insulate it with some ceramic board, then set the old slab/oven on top. It would give you a lot of mass to heat but it would work.. Then you would insulate the dome like normal..

[CajunKnight]

Re: Help! Trying to make the best of a bad situation

onething to keep in mind when adding board and brick to floor... is door going to be high enough? and if dome isnt covered yet would it be possible to relocated vent to arch opening?

[maver]

Re: Help! Trying to make the best of a bad situation

Just for a point of reference for what you are trying to avoid, my father also has an uninsulated floor placed on a concrete slab with an uninsulated dome. His oven is able to be heated to pizza temps, but it take 2-3 hours vs about an hour for mine. During those 2-3 hours he has to feed the oven quite a bit of wood. Incidentally, his vent is from the top of the dome rather than over the opening as most use here. His dome is (I think) 46" and he needs the extra room because he has to keep a very big fire. All that said, his pizza is very good and was enough to inspire me to build my oven. I believe the dome insulation (and avoiding a vent in the dome) are the most important steps. If you can also insulate under the floor bricks as well you are golden.