Started my Build in Georgia

[david s]

Re: Started my Build in Georgia

Hi David,

there is no way an insulated structure will benifit in the eliminated of moisture .

Except as previously explained, the insulation will help even out the temperature difference.
It will certainly reduce the rate at which the moisture is removed. Castable refractory manufacturers recommend that when eliminating moisture, if steam is visible then you are going at it too hard and to back the heat off. Presumably the same would apply for the mortar in an oven constructed of brick.
Like I said before, you can do it quickly and risk damage, but you can never do it too slowly.

I've certainly built defects in things , but I'm sure I've never been guilty of defection.

[Laurentius]

Re: Started my Build in Georgia

Hi David,

Thank you for your observation, I think that most people become obsessed with their sweat and toil and forget that their oven is just a tool, and just like us it develops many defections as we go along. In Japanese "Wabi, sabi", is a good thing. If you follow the principle of physic there is no way an insulated structure will benifit in the eliminated of moisture over a non insulated one, its intuitive to think that way but not based on science.

[DavidApp]

Re: Started my Build in Georgia

Hello Laurentius and David S.

I had seen the insulation on or off curing discussion so I decided to put 1 layer on after several heating cycles thinking that most of the moisture had been driven off. Also I had finished the construction almost a month ago and the oven is under cover so it had never been rained on so I thought a lot of the moisture would have dried out naturally.
I was surprised to see beads of moisture forming on the insulation. It was cold that day. The temperature difference should have given me a clue that the lower half of the oven was still damp and I should do low heating till the temperatures were more similar.
I have my insulating door now and have allowed the heat to soak through the oven. Still at 180 in the lower part of the dome almost 24 hours after the fire went out.

The door is made from some steel shelving material formed into a 2" tray. I put 1 layer of fiber board and one layer of ceramic fiber blanket in the tray then screwed it to the wooden outer panel.

Cooked a chicken and did some home fries. They were good.

David

[david s]

Re: Started my Build in Georgia

The advantage of drying the oven with the blanket on is that it helps even out the temperature. As the top of the oven will dry first then there is a massive temperature difference between it and the base of the dome and the outer perimeter of the floor. This leads to a massive difference in expansion too, which is undesirable because it creates great stress which can lead to cracking. In addition, if your outside ambient temperature is low and you also have wind on the outside of the oven creating wind chill factor, the temperature differential will be much bigger than if you have it insulated. Allowing the whole oven to return to ambient and possibly some remigration of moisture from the moister parts to the dryer parts is also helpful. Whatever way you do it (uninsulated or insulated) take it slower than you would think. You can do it quicker and risk damage, but you can never do it too slow.

[Laurentius]

Re: Started my Build in Georgia

Hello Texman

I have kept them. In fact I still have the paper profile that I used to make a cardboard template to check the fit.

I am going to make a mild steel inner door about 1/16" thick. There will be a 2" space for insulation then the outer door. The outer part of the door will close against the reveal to form the seal.
I will post photos when it is done. Maybe during construction if it goes well.

Got up to 550/600 degrees today and held it for an hour or so. Was surprised to see beads of condensation on the insulation blanket. It was about 40 degrees so I suppose condensation is to be expected. Makes a good argument for not putting the final render till everything has fully cured. I should probable had a few more fires before I put some of the blanket on the oven.

Found my beer butt chicken stand. May try to cook a chicken with a live fire tomorrow.


David

Hi David,

Its more efficient to fire it up without the blankets to drive out the moisure than it is with the blankets. Remember insulation is a barrier for getting out as well as getting in!

[Greenman]

Re: Started my Build in Georgia

Hello Steve

Thank you.

The box of blanket I ordered was $55.00 same as the original box. They are a lot cheaper than other places I looked at on the internet. It is the 2300 degree f Inswool -HP 6#

I have been spending a lot of time on the cooking section. I am looking for my beer butt chicken stand. I put it away some time ago and can't remember where I put it. May have to get a new one so I can use some of the heat on Friday.

David

That is about half the price of it here.

Good that you found the chicken stand. You have the temps to use it and it would be a pity to waste the heat.

[DavidApp]

Re: Started my Build in Georgia

Hello Texman

I have kept them. In fact I still have the paper profile that I used to make a cardboard template to check the fit.

I am going to make a mild steel inner door about 1/16" thick. There will be a 2" space for insulation then the outer door. The outer part of the door will close against the reveal to form the seal.
I will post photos when it is done. Maybe during construction if it goes well.

Got up to 550/600 degrees today and held it for an hour or so. Was surprised to see beads of condensation on the insulation blanket. It was about 40 degrees so I suppose condensation is to be expected. Makes a good argument for not putting the final render till everything has fully cured. I should probable had a few more fires before I put some of the blanket on the oven.

Found my beer butt chicken stand. May try to cook a chicken with a live fire tomorrow.


David

[texman]

Re: Started my Build in Georgia

Looks like some good times on that roof. That chimney height will make the oven draw very good. Keep your arch templates to build your doors for the oven.

Texman

[DavidApp]

Re: Started my Build in Georgia

Hello Steve

Thank you.

The box of blanket I ordered was $55.00 same as the original box. They are a lot cheaper than other places I looked at on the internet. It is the 2300 degree f Inswool -HP 6#

I have been spending a lot of time on the cooking section. I am looking for my beer butt chicken stand. I put it away some time ago and can't remember where I put it. May have to get a new one so I can use some of the heat on Friday.

David

[Greenman]

Re: Started my Build in Georgia

Looks good David. I don't think that there is such a thing as too much insulation. I guess it depends on how deep your pockets are. That stuff is quite expensive in this part of the world.

By now you should be seriously studying pizza dough recipes.

[DavidApp]

Re: Started my Build in Georgia

Hello All

I am through the roof with my chimney. Not too happy working on the roof that close to the edge so I made a roof ladder so that I would have something to hang on to. The ladder was tied to the truck and I do have the truck keys in my pocket.

Had my first real fire, I had been heating with a LPG burner for several days. I got the dome to about 450degrees and kept it there for over an hour. Several hours later it is still hot.

Put the first layer of blanket on the oven and was suppressed how much moisture was coming out of the oven. I had to order a second box of blanket as one box will not be enough so I may be able to do 4" of blanket. I presume more is better?

Tomorrow I will fire it again to about 550.

[DavidApp]

Re: Started my Build in Georgia

Hello Texman

It is Dura Vent double wall insulated pipe. The type that Forno Brovo sells.

I am maintaining more than the minimum clearance around the pipe and will probable box the pipe in with Concrete board in the attic space.

I will keep a watch on the chimney temperature.

David

[texman]

Re: Started my Build in Georgia

is that triple wall or double wall pipe? she gets really hot and just want to make sure you have plenty of clearance to the combustibles.

[DavidApp]

Re: Started my Build in Georgia

Hello All

Got my 6" Dura Vent chimney pipe to go through the breezeway ceiling and roof.
Did the modifications to my ceiling and roof structure to allow the chimney to pass through.

Started to heat the oven using a LPG gas burner. I notice that the dome gets up to about 300f but the lower areas of the dome hardly get above 90 to 100f. Today while I had the gas burner fired up I noticed a dark line in the mortar about 4 chains up from the hearth. Is this moisture coming out of the bricks?

Once I have the chimney finished I can start with wood fires.

David

[DavidApp]

Re: Started my Build in Georgia

I have just scored some fuel for the oven. Some of the logs are 30" diameter.

Have to get the oven finished so that I can use the wood. I do have a fire wood pile so I will not have to wait for this to dry.

David