New Project With So Many Questions

[robinhood]

I saw a Youtube Video on how to make an oven and I thought that doesn't look too complicated.

I have purchased a load of materials but started to do some more in depth research and now I am beginning to panic that I might do things wrong and waste money and materials I have bought. 

I was planning on using a perlite cast around an exercise ball, but now having researched thermal mass I am worried it will lose its heat pretty quick.

I have a load of heat storage bricks, I am now wondering if I can use them to create the dome using fire cement and then cover it in perlite, use a ceramic sheet as insulation and then another layer or perlite then fire cement/render and paint.

What is the difference between perlite and vermiculite? I cant seem to identify the difference but a lot of the posts on here refer to vermiculite rather than perlite
Can I use concrete fibers rather than rebar for my concrete foundations? 
Would you recommend using standard bricks rather than concrete blocks? 
Do I require a ceramic board underneath the fire bricks for the floor inside the oven? I was intending on just using a sand/clay mix
Once dried out how do I ensure it stays water free, can I put a layer of water protection on the outside? 
How big does the flue need to be I am intending on a 65CM dome? 
Does the Flue need to be metal or can I use a pottery type one? 

Any help from WFO guru's would be much appreciated for a novice like me

[downunderdave]

Mar 5, 2021 14:44:42 GMT robinhood said:

I saw a Youtube Video on how to make an oven and I thought that doesn't look too complicated.

I have purchased a load of materials but started to do some more in depth research and now I am beginning to panic that I might do things wrong and waste money and materials I have bought. 

I was planning on using a perlite cast around an exercise ball, but now having researched thermal mass I am worried it will lose its heat pretty quick.

I have a load of heat storage bricks, I am now wondering if I can use them to create the dome using fire cement and then cover it in perlite, use a ceramic sheet as insulation and then another layer or perlite then fire cement/render and paint.

What is the difference between perlite and vermiculite? I cant seem to identify the difference but a lot of the posts on here refer to vermiculite rather than perlite
Can I use concrete fibers rather than rebar for my concrete foundations? 
Would you recommend using standard bricks rather than concrete blocks? 
Do I require a ceramic board underneath the fire bricks for the floor inside the oven? I was intending on just using a sand/clay mix
Once dried out how do I ensure it stays water free, can I put a layer of water protection on the outside? 
How big does the flue need to be I am intending on a 65CM dome? 
Does the Flue need to be metal or can I use a pottery type one? 

Any help from WFO guru's would be much appreciated for a novice like me


The perlite cast around an exercise ball results in a weak casting with very little thermal mass, neither are good qualities for an oven with a planned long life. Your second option is far more preferable.
Perlite and vermiculite are interchangeable with similar characteristics and price. Use either or a mix of both which I find creates a better mix.
Use steel rebar for foundations.
Concrete blocks give you height more easily and if you don't have block laying skills you can use masonry adhesive because the cores in the corners and every second core are usually filled with concrete.
It is essential to insulate between the floor bricks and the supporting slab. The sand/clay mix is only a leveller to compensate for uneven floor brick thickness.
If the cost of calcium silicate board scares you too much you can lay your own insulating slab from 5:1 vermicrete (or perlcrete) but it needs to be 100 mm thick to achieve the same insulation value as 50mm of cal sil.
A roof is the best way to keep out moisture, but is also the most expensive. Most oven owners ovens are out in the weather. There are numerous waterproofing products.
A 65 cm internal diam dome requires a 150mm (6") flue pipe.
If metal use stainless or you'll be replacing it down the track. If clay it must be insulated on the outside or it will crack.

Do plenty of research before committing to any plan.