Perlite Ratio

[Shay]

Hello everyone

What is the ratio of perlite, cement, and sand to build a pizza oven dome?
What is the thickness required to build the dome before the layer insulation?



Thanks

[david s]

Re: Perlite Ratio

Hello everyone

What is the ratio of perlite, cement, and sand to build a pizza oven dome?
What is the thickness required to build the dome before the layer insulation?



Thanks

If you build the dome with perlite in the mix it will not be dense enough to store heat.
Generally the dome thickness is between 2-4" thick depending on the materials used.
Suggest you download the free plans or read lots of build threads to get a better idea of design principles.

[Shay]

Re: Perlite Ratio

Thanks

I have just design and built the first arc already (attached a picture)
Now I have to build the rest of the oven and I wanted to build from perlite and cement
But I do not know about the right ratio

[brickie in oz]

Re: Perlite Ratio

Like David said, you cant build an oven out of perlite and cement, it just wont work.

[Shay]

Re: Perlite Ratio

if so what are my options instead if I do not want to
build from bricks?

[david s]

Re: Perlite Ratio

Use a dense castable refractory. Search the forum for this material and read all you can. You can buy the stuff from a refractory supplier.

[Johnny the oven man]

Re: Perlite Ratio

Perlite and its neighbour Vermiculite are insulators, and wont hold heat. As David S mentioned use a Refractory dense castable, a 1350c grade is most likely the easiest and cheapest option. approx $25-$30/25 kg bag.Dont know the size of your oven, but if you calculate the volume of the prefered dome, you can use the 80 bags/m3 figure to work out your requirement, or if your old like me, 2 bags/Ft3. THEN use your Perlite mix over that dome to keep the heat in.

[Brando23]

Hello,. I am new to the community .I have started a perlite oven project based on youtube videos. I used the yoga ball method but am now through the wonderful resources on this site, realizing that the perlite cement mix used for the oven is not a good option. I have already used it over the yoga ball and am currently wet curing it for a week. I'd hate to start all over . I am wondering if could use a refractory cement to coat the outside of the perlite mold to salvage the project? Home Depot has a refractory cement I was thinking to use? Thanks for the advise

[UtahBeehiver]

We see the YouTube v or pcrete dome pop up periodically on the forum. As you have figured out, it is not your best option, The main issue in the interior surface is not stout enough to stand up to the banging and abuse of firing, IE, wood loading, peels, etc. Some builders have tried to skim coat the interior with a refractory material but as far as we know it is not successful. There is not a lot of follow-up from builders who build a p or vcrete dome so my guess it is not very successful long term. I would take a step back and see if this is really the direction you want to go, There have been a number of good refractory cast oven built recently on the forum if brick is not in the cards.

[Allan scott]

Hi just wondering if I could pour a refractory cement base instead of fire bricks it would be cast on top of a perlite. 40 mm Insolated base thanks allan

[david s]

You could, but there are two problems. Firstly the floor takes much more of a beating than the dome and unless you have access to a kiln to sinter the casting really slowly it will be more subject to cracking and spalling. The second problem is that the larger the casting the greater the propensity to crack due to uneven heating. For these reasons a loose laid floor of fire brick is a superior solution.

[HilbornJ42]

Can you use 1/2” steel for the floor?