My first attempt for 42" oven / changed to 36"

[SableSprings]

Why some builders put foil between perlcrete and floor?
Is it necessary to put foil?"

Some of the builders 20-25 years ago recommended the addition of foil layer between the refractory material and the outside (insulating) cladding. This was to provide slip between layers during the expansion/contraction of the oven chamber during use. As David S above noted, using foil between the hearth and floor insulation doesn't make any sense. Using it between the concrete stand and the bottom of the insulation layer might inhibit water from wicking up into the insulation but wouldn't be your best option. There were also recommendations 20-25 years ago of using diatomaceous earth to provide this slip layer...its supposed advantage was that it would fill minor cracks that formed during expansion and could be applied a bit more thickly...

I actually used the diatomaceous earth method as a slip layer between my oven brick and the outer top layer of insulating perlcrete for my oven. I had it on hand and didn't spend a lot of time on the forum investigating or asking the question of "Is it worth it?" before starting my build . I don't think it made any difference and it certainly was a pain in the a__ to apply.

[George_M]

Today i made some thoughts to start build the first arc and first row of the dome.
I need your advise on this.
On the second picture,which is the ideal method to close the dome with the arc?

[deejayoh]

Check out the pictures linked in this post, and look up Gianni's Octoforno build. This approach will save you much grief in the build. good luck!

https://community.fornobravo.com/for...724#post355724

[George_M]

Thanks deejoyh,finally i did as pizza bob's idea. https://community.fornobravo.com/fil...photoid=275921

I did good progress yestertaday and today!
I think my oven is in a good way..

[George_M]

[George_M]

[George_M]

[George_M]

[George_M]

Next step is the first arc.
I have a small reveal if you see above for the door.

[UtahBeehiver]

George,

You are doing a great job keeping the oven course staggered. Impressed you are just using a string for guidance, just goes to show ya simple can work just as well. Have you given thought of doing a tapered inner arch for you oven? Attached is pic from Mr. Chipster's build showing an tapered inner arch similar to your. Highly recommended to do one. It makes the dome to arch tie-ins much smoother.

[George_M]

Thanks my friend!I appreciate your help!
I plan to make like this https://community.fornobravo.com/fil...photoid=276946
I think it is easy..
The bricks at the next row will lock in the arc like the photo in the link.

[UtahBeehiver]

Don't want to burst the bubble but it looks easy but will be much more difficult than it seems. They are very complex angles and difficult to do. But it is your choice.Research tapered arches and look how smooth the transitions can be.

[david s]

George, your mortar looks very dark. Have you added lime and clay or are you just using sand and cement?

[George_M]

Don't want to burst the bubble but it looks easy but will be much more difficult than it seems. They are very complex angles and difficult to do. But it is your choice.Research tapered arches and look how smooth the transitions can be.

Hmm..I will think it again to do like this.

[George_M]

George, your mortar looks very dark. Have you added lime and clay or are you just using sand and cement?

David,I use calcium aluminate cement with chammotte (sand from bricks) 1:3 .The store where I bought it told me to use this ratio without lime,only this..
This is not Portland cement .