Insulating existing barrel oven

[scaylabs]

Hello everybody,

First of all, I have to say that finding this site has been a real eye opener, just wish I had found it sooner!

My Argentinean father-in-law came for a visit a couple months ago and decided that his project while he was here would be to make a simple outdoor kitchen, consisting of a sink, grill and oven.

Here's what it looks like so far (many details left to go)


I have used the oven several times with no issues, several roasts and lately a couple pizzas, which prompted me to look for some appropriate pizza making techniques, which in turn lead me to this site and the crazy temperatures some of you are seeing several days after firing!

Of course it didn't take much reading to realize that my oven has zero insulation, it's basically very old Chicago brick held with mud and covered in cement.

Now, the question becomes, what can be done to insulate it now?

Thanks for your input!
Andres

[scaylabs]

Re: Insulating existing barrel oven

Here is another picture (with the chimney still under construction) showing the other side:

[scaylabs]

Re: Insulating existing barrel oven

Well, it looks like I will be doing a 3-4" layer of Perlcrete over the vault.

You can see on the picture that most of the left side of the oven (facing it) is next to the grill wall, so there is nothing I can do there. I will keep loosing heat through that wall.

I can only improve the rest.

I would like some ideas on the bottom of the oven though. I was thinking of casting a 4" slab of Perlcrete on top of cement board and then lifting it into place, holding it with some angle iron.

[texman]

Re: Insulating existing barrel oven

i have a house full of old chicagos and they tend to spall at normal temps. Have you had any trouble with them from the heat? As you insulate, you will be able to sustain higher temps for longer periods and will definitely put your bricks and mud to test. Worst case it fails and start over, but i would try what you have.

Texman

[Tscarborough]

Re: Insulating existing barrel oven

Yes, I would just go with what you have and maximize the potential as is.

[Laurentius]

Re: Insulating existing barrel oven

Hi Scaylabs,

If I was you and I'm assuming that you are not Argentinean. I would consult with my father-in law and sing praises of his project and how it has enhanced your life, then carefully broach, how you would would love to bake bread and slow cook a variety of stews, and meats that can be only achieved with a well insulated oven. Tell him that you will do the research, with his approval. Otherwise, you might be viewed as a all knowing, wise assed, American(another assumption) know it all, who has no business being married to his precious little girl, the light of his light. Be very careful when dealing with in-laws from other cultures, take it from me, I'm learning sometime new, daily. After you do this, then and only then can we give you the necessary advice, you seek.

[brickie in oz]

Re: Insulating existing barrel oven

After you do this, then and only then can we give you the necessary advice, you seek.

Pull it down and build it properly.....

[scaylabs]

Re: Insulating existing barrel oven

Hi Scaylabs,

If I was you and I'm assuming that you are not Argentinean. I would consult with my father-in law and sing praises of his project and how it has enhanced your life, then carefully broach, how you would would love to bake bread and slow cook a variety of stews, and meats that can be only achieved with a well insulated oven. Tell him that you will do the research, with his approval. Otherwise, you might be viewed as a all knowing, wise assed, American(another assumption) know it all, who has no business being married to his precious little girl, the light of his light. Be very careful when dealing with in-laws from other cultures, take it from me, I'm learning sometime new, daily. After you do this, then and only then can we give you the necessary advice, you seek.

Thanks for the chuckle Laurentius . Believe me, I have considered that aspect of the project carefully. I definitely don't want to offend him after he spent all this time building it.
I am handling it very diplomatically. Fortunately we are of very similar cultures so I have it a lot easier than you!

[scaylabs]

Re: Insulating existing barrel oven

Completely frustrated with Perlcrete. This stuff is virtually impossible to work on the vertical or it's me that is useless with it?!
My dome is vertical for the first foot or so, and I can't even make it to that point. Smaller spaces like around the oven opening are easier, but still, any false move and half the wall comes crumbling down.

I'm done for today... fingers cut from the metal lath and stiff from the cement.
I might bite the bullet and order the ceramic blankets and just use perlcrete under the oven floor.

[brickie in oz]

Re: Insulating existing barrel oven

Completely frustrated with Perlcrete. This stuff is virtually impossible to work on the vertical or it's me that is useless with it?!
My dome is vertical for the first foot or so, and I can't even make it to that point. Smaller spaces like around the oven opening are easier, but still, any false move and half the wall comes crumbling down.

I'm done for today... fingers cut from the metal lath and stiff from the cement.
I might bite the bullet and order the ceramic blankets and just use perlcrete under the oven floor.

I really dont know why ppl bother with pearlcrete/vermicrete it seems to create more problems than it solves.

[Gulf]

Re: Insulating existing barrel oven

Completely frustrated with Perlcrete. This stuff is virtually impossible to work on the vertical or it's me that is useless with it?!
My dome is vertical for the first foot or so, and I can't even make it to that point. Smaller spaces like around the oven opening are easier, but still, any false move and half the wall comes crumbling down.

I'm done for today... fingers cut from the metal lath and stiff from the cement.
I might bite the bullet and order the ceramic blankets and just use perlcrete under the oven floor.

Pcrete/Vcrete (I only have experience with Vcrete) on the vertical needs a foundation underneath for it to rest. Looking at your pics, I am wondering if you are supporting it. If not, you will only be able to add about an inch to the thickness at a time. I was able to apply a 3 to 4 " thick layer to my dome. I began with plenty of support from underneath and only climbed about six inches per course. Beginning on one side of the dome and completing the course on the other. This gave the Vcrete time enough to set up to support the next course.
I hope this helps.

[scaylabs]

Re: Insulating existing barrel oven

Gulf was right on the money. Thanks for his comment on supporting it from below and someone else on the forum suggesting using forms I was able to get it done.



I'll swap that 2x4 supporting the right side by cement board before I stucco.

Here's what I did to help me place that bottom perlcrete slab:

I put a fresh coat of mortar on top of the slab, lowered the supports about 1.5" in order to slide the slab in, then lifted it by turning those nuts.

Stucco is next and finishing the insulated door.

Oh, and yesterday I made my first decent pizza after finding a local market that carries Caputo flour. Day and night.


Happy camper :-)

[cobblerdave]

Re: Insulating existing barrel oven

Gudday
Well done I'm impressed .....particularly with you bottom slab well thought through well executed

Regards dave

[scaylabs]

Re: Insulating existing barrel oven

Gudday
Well done I'm impressed .....particularly with you bottom slab well thought through well executed

Regards dave

Thank you Dave! I think it came out pretty decent all things considered.

Below you can see how the door is coming along. Ignore the ugly welds and peeling paint please; that is all reclaimed sheetmetal from an old grill (the stuff at Home Depot was too thin to weld) so it will be ground and repainted when I'm done.




I made those 1/4" gaps between the inner and outer sections (first pic) to minimize heat transfer. The sections are only joined at the corners by 1.5" of metal.
Then I used some left over fiberglass header wrap (found at autopart stores) to line the gaps from the inside to keep the 2" of perlcrete in, and on the outside I'll use fiberglass rope gasket to finish the seal.

The "pretty" side will be red oak and a 5" thermometer in the center.

[Ar6entino]

Re: Insulating existing barrel oven

Hello,
I would like to know details on the chimney you have made out of sheet metal like if you have details on how you made it. Thanks!