Work of Love and Passion... Miami FL

[gugahulk]

Re: Work of Love and Passion... Miami FL

Base getting ready for concrete. Please any advice would be great. See the pictures below and if I am doing anything wrong now is the time... :-) Look forward to any comments.

[BuilderMakerCreator]

Re: Work of Love and Passion... Miami FL

Hello,

Another super low cost insulation available to you is to use Perlite (2 cu-ft bag from Home Depot or Lowes for $16 or a 4 cu-ft bag for $10 at Atlantic FEC in Homestead, Fl). You could use sodium silcate as a high temp binder or any other high temp adhesive/aggregate, or simply use it loose to fill the gaps. It will add NO STRENGTH to the structure, but it does provide very good insulation. I've seen it used as a loose fill between two structural domes (one inner, one outer) which helped with thermal expansion as well. The outer dome didn't even melt the snow atop it when the owner fired up his oven. The better part of perlite as an insulation is its lightweight. A 2 cu-ft bag weighs approx. six pounds.

Perlite will reduce the heat within the oven from passing through the walls where you place it. It WILL NOT act as a temp holding medium/mass like clay, stone, marble, iron, etc. Something has to absorb all of that heat so it can in turn radiate back into the oven space when the fire has expired. In other words, if you replace too much of the inner heat absorbing mass of your oven with heat resistant mass (insulation) your oven will heat up faster during firing, and cool faster when the heat source dies out. You won't have that nice heat soaked oven effect we all seek.

[DavidApp]

Re: Work of Love and Passion... Miami FL

Did you leave the door in place for the whole test of the charting?
Was the wind and outside temp about the same for the duration of the test?

Hello Chip
The door was in place all the time except for loading the oven or checking the temperature.
The oven is in the breezeway so it is not effected by wind that much and the ambient temperature was in the high 60s to low 80s.

I was comparing the results of the 2" door to the 4" door. I am noticing that the temperature profile changed depending on how long I fire the oven.

David

[mrchipster]

Re: Work of Love and Passion... Miami FL

Just sent you a PM. Call me.

[gugahulk]

Re: Work of Love and Passion... Miami FL

We have a disconnect going on here. I need to ask you a couple of questions.

Are you building your dome on top of your floor? or are you building your floor inside the dome and cutting the floor into a round shape?

I was planning on building the floor inside of the side walls. Which way do you recommend?

[mrchipster]

Re: Work of Love and Passion... Miami FL

First of all thanks for this! Grateful for this knowledge, question why whould I put a vapor barrier of cardboard under the slab? than the slab it self will not be attached the the bricks. Did I understand this correctly? There should be no heat at all there.

And the first layer of bricks on the dome and floor of the oven will not have any motar at all? I understand replacing the bricks on the floor of the oven but how would I ever replace the side? unless there is another reason for it doesn't make sense to a novice like me. Sorry for the question... and thank...

We have a disconnect going on here. I need to ask you a couple of questions.

Are you building your dome on top of your floor? or are you building your floor inside the dome and cutting the floor into a round shape?

[gugahulk]

Re: Work of Love and Passion... Miami FL

Play sand is to coarse. HD has fine sand just ask for it.

Vapor barrier. Simply plastic 4 mil is fine. Sold as drop cloth plastic in paint department as sheets or large rolls for vapor barrier in construction. Place on top of your stand just before you pour your slab.

Look at the drawing again. Corrugated cardboard between oven wall and floor.

Wow, you are very helpful, I really appriciate the comments. I hope to one day meet you here in miami, love to take you fishing and test the oven once all is done. Some fishing pictures below maybe you have an excuse to come down one day...

[gugahulk]

Re: Work of Love and Passion... Miami FL

First --- Everything hot should only touch insulation. And to be safe cut your insulation board about 1 inch larger than the outermost bricks of your oven (if possible).

Second Gravity holds the board in place. Once you put 1000 pounds of brick on it. Well let's just say it would be difficult to move.

Third. Level your firebrick with a thin layer of fine sand and mixed with fire clay if you like. Use a notched trowel like used for tile work to allow you to easily level the bricks.

Do not mortar under the first row of dome bricks. Also place a spacer of corrugated cardboard between dome and floor to provide an expansion gap. The cardboard will burn out and fill with ash over time.
******************
I am not sure I agree with the vapor barrier comment above unless it was a piece of thin stainless steel. Iron/steel will rust, and other materials well ... there is still a great deal of heat nearby. Your slab should be kept dry from the outside and if you have moisture in your slab that needs a vapor barrier you have other problems.

I do agree that your stand and the slab under the oven should have a vapor barrier but that is in a cool area and prevents wicking from the ground.

First of all thanks for this! Grateful for this knowledge, question why whould I put a vapor barrier of cardboard under the slab? than the slab it self will not be attached the the bricks. Did I understand this correctly? There should be no heat at all there.

And the first layer of bricks on the dome and floor of the oven will not have any motar at all? I understand replacing the bricks on the floor of the oven but how would I ever replace the side? unless there is another reason for it doesn't make sense to a novice like me. Sorry for the question... and thank...

[mrchipster]

Re: Work of Love and Passion... Miami FL

Wow this is valuable information, thanks. I am not able to find fireclay any where, can I just use play sand from home depot?

The vapor barrier how should I ad that?

So my oven will not be attached at all to the base, it will be completely help down by its weight. Only once I stucco it and it will be permanent correct? The vapor barrier is between the side walls of the oven and the floor of the oven? I need to understand this better as I don't understand why. Thanks again this never crossed my mind.

Play sand is to coarse. HD has fine sand just ask for it.

Vapor barrier. Simply plastic 4 mil is fine. Sold as drop cloth plastic in paint department as sheets or large rolls for vapor barrier in construction. Place on top of your stand just before you pour your slab.

Reason for vapor barrier is that moisture will wick up through the concrete in contact with the ground and cause the slab under the oven to become damp, this moisture will reduce the efficiency and insulating power of your ceramic board.

For this reason you also want to waterproof the top of the slab your oven sits on so rain does not penetrate that slab.
Pay particular attention to waterproofing the seam that will exist between the oven and the slab. It is a common location for rain to seep in.

Look at the drawing again. Corrugated cardboard between oven wall and floor.

[gugahulk]

Re: Work of Love and Passion... Miami FL

Hello

The Insulation should go on a vapor barrier. It just sits there held in place by the weight of the oven.

The Fire brick go on a layer of fine sand/fire clay mix to level the bricks. The same as you would lay pavers.

The Oven walls should also go on the Insulation. You can either have the walls sit on the floor bricks or on the insulation. Both ways have advantages and disadvantages. If the walls and floor are separate you can replace floor bricks if they get damaged.

This is my temperature profile early version. The blue line is with a 2" door the red line is my new 4" door.

David

Wow this is valuable information, thanks. I am not able to find fireclay any where, can I just use play sand from home depot?

The vapor barrier how should I ad that?

So my oven will not be attached at all to the base, it will be completely help down by its weight. Only once I stucco it and it will be permanent correct? The vapor barrier is between the side walls of the oven and the floor of the oven? I need to understand this better as I don't understand why. Thanks again this never crossed my mind.

[mrchipster]

Re: Work of Love and Passion... Miami FL

This is my temperature profile early version. The blue line is with a 2" door the red line is my new 4" door.

David

Did you leave the door in place for the whole test of the charting?
Was the wind and outside temp about the same for the duration of the test?

[mrchipster]

Re: Work of Love and Passion... Miami FL

Little lost about the insulation board. Try to find a thread but didn't. How do I attached the insulation board to the concrete slab? with nothing? it just sits on it? How is it glued on the slab?

Also I plan on using the firebricks right on top of the insulation board, is that the best way? should the walls of the oven be layed directly on the concrete slab or better in the insulation board? Any input would be appreciated.

First --- Everything hot should only touch insulation. And to be safe cut your insulation board about 1 inch larger than the outermost bricks of your oven (if possible).

Second Gravity holds the board in place. Once you put 1000 pounds of brick on it. Well let's just say it would be difficult to move.

Third. Level your firebrick with a thin layer of fine sand and mixed with fire clay if you like. Use a notched trowel like used for tile work to allow you to easily level the bricks.

Do not mortar under the first row of dome bricks. Also place a spacer of corrugated cardboard between dome and floor to provide an expansion gap. The cardboard will burn out and fill with ash over time.
******************
I am not sure I agree with the vapor barrier comment above unless it was a piece of thin stainless steel. Iron/steel will rust, and other materials well ... there is still a great deal of heat nearby. Your slab should be kept dry from the outside and if you have moisture in your slab that needs a vapor barrier you have other problems.

I do agree that your stand and the slab under the oven should have a vapor barrier but that is in a cool area and prevents wicking from the ground.

[DavidApp]

Re: Work of Love and Passion... Miami FL

Hello

The Insulation should go on a vapor barrier. It just sits there held in place by the weight of the oven.

The Fire brick go on a layer of fine sand/fire clay mix to level the bricks. The same as you would lay pavers.

The Oven walls should also go on the Insulation. You can either have the walls sit on the floor bricks or on the insulation. Both ways have advantages and disadvantages. If the walls and floor are separate you can replace floor bricks if they get damaged.

This is my temperature profile early version. The blue line is with a 2" door the red line is my new 4" door.

David

[gugahulk]

Re: Work of Love and Passion... Miami FL

Little lost about the insulation board. Try to find a thread but didn't. How do I attached the insulation board to the concrete slab? with nothing? it just sits on it? How is it glued on the slab?

Also I plan on using the firebricks right on top of the insulation board, is that the best way? should the walls of the oven be layed directly on the concrete slab or better in the insulation board? Any input would be appreciated.

[gugahulk]

Re: Work of Love and Passion... Miami FL

Hello

I am not familiar with that brand but you should be OK with Maimizer as it is a 5600lb mix.

The cooking floor height looks good. If it is too low your view will be obstructed and if it is too high working the oven will be harder.

I am keeping a record of my oven temperature so that I will have a better idea when to schedule my cooking.

David

Awesome thanks, yes let me know about the temperature, look forward to knowing it.