Internal rendering

[7.62]

Hi guys.

Lots of good information on this forum, although I am having some trouble finding what I am looking for.

I have built a friend a wood oven, and its simply not getting hot enough. I am going to lay some half height fire bricks in the oven today, but I know there is a LOT of heat escaping through the bricks up the top, after all, they are hand mades.

My question is, what would be the best product to render the inside of the oven with?

Thanks in advance.

[moderator]

Re: Internal rendering

Hi 7.62,

What a wonderful question. What we would suggest is applying our insulating blanket (at least 2 layers) to the top of the dome. This will dramatically reduce the amount of heat escaping from your oven. Also, do you insulation under the oven? This will also help keep the heat in.

Amber :-)

[Ken524]

Re: Internal rendering

Amber is right. You don't want to render the interior of the oven. Insulation outside will seal it up nicely.

[Laurentius]

Re: Internal rendering

Hi 7.62,

If you give us more details in how you built the oven then we would be in a better position to give advice. Do you have any photos that you can show us?

[7.62]

Re: Internal rendering

I do have pictures, they are on my phone. NOt sure how to upload them.

I made the oven from hand made bricks. I know they are not the most heat retaining material, but being in a small country town, thats all I had.

The oven is now insulated using Cilica st-somthing and 25mm refractory bricks.

My issue is the dome. I was inside the oven today, so what can I render the inside with to thermo insulate the dome?

[moderator]

Re: Internal rendering

Hi 7.62,

I can fully understand your position in wanting to render the inside of the oven. However, we highly suggest against it. With our ovens we insulate over the dome and under the cooking surface and this works fantastic for us. If you could do this instead of the rendering you will have great thermal retention.

Amber :-)

[7.62]

Re: Internal rendering

Thanks for the good advice Amber.

Here is an image I managed to upload. The customer wanted a rustic look, and they love the finish, and this is why they do no want to render the outside.

[deejayoh]

Re: Internal rendering

There isn't anything that you can use to render inside the oven. Any material will crack and spall in the heat.

I'm not sure what you meant by your comment about the cal-sil insulation. From appearances there is no insulation on the dome. to improve performance you will need to insulate the dome. If you don't want to change the appearance, then you will have to live with poor performance.

[brickie in oz]

Re: Internal rendering

The flue is in the wrong spot too, all the heat will be rushing out the top of the oven.

[7.62]

Re: Internal rendering

Hi there deejay.

I have bought some calcium silicate board, and those firebricks you can see. The board is arriving monday, and they will be installed in there then.

[7.62]

Re: Internal rendering

Bricky,

There is a baffle system on there too, steel plate moved with a cable.

EDIT - I enjoyed reading your wiki too, where did that go?

[brickie in oz]

Re: Internal rendering

Without insulation over the top it will never stay hot.

[7.62]

Re: Internal rendering

Brickie, I dont need it to stay hot all day really, I only need it to get hot enough to cook pizza.

Where did your briki wiki go? I used to read that....

[Laku]

Re: Internal rendering

Firebricks aren't insulation. And you really really want to have insulation or it will take a forest of wood to get in temp. And even then it will not perform good.

[mrchipster]

Re: Internal rendering

Firebricks aren't insulation. And you really really want to have insulation or it will take a forest of wood to get in temp. And even then it will not perform good.

You are also going to be sucking heat into the slab out of the dome because the dome is sitting directly on the slab. There are a great number is serious issues with this oven design.

Chip