Sand Casting question

[gunnarmcc]

Hi all

i finally convinced the wife that having a WFO in the back yard was a good idea. Im just in the planning stage but plan on casting on site over a sand mould. My question is about the casting mix. if i purchase a castable refractory something like rutlands https://www.homedepot.com/p/Rutland-...-601/300981816 do i cast a thinner "oven wall" say 2 inches thick and then continue to add a mix of portland cement and vermiculite over the top to get my overall desired thickness in the dome?
many thanks
gunnar

[Allie]

Did you use Rutlands cement? If so, how did it work/ hold up?

[david s]

Hi all

i finally convinced the wife that having a WFO in the back yard was a good idea. Im just in the planning stage but plan on casting on site over a sand mould. My question is about the casting mix. if i purchase a castable refractory something like rutlands https://www.homedepot.com/p/Rutland-...-601/300981816 do i cast a thinner "oven wall" say 2 inches thick and then continue to add a mix of portland cement and vermiculite over the top to get my overall desired thickness in the dome?
many thanks
gunnar

You should be able to get a better deal from a refractory supplier.
A ceramic fibre blanket over the inner dome and then a vermicrete layer over that is a better way to go than placing wet vermicrete against the inner dome. Firstly the ceramic fibre blanket can act as an expansion joint and secondly it is already dry. If wet vermicrete gets suddenly hot the steam created can make it swell and crack. But with a layer of blanket underneath this problem is removed.

[Hatter]

Can you recommend an oven that fits what you just described here please, David? Cheers!

[david s]

Try starting here, on this well documented build.
https://community.fornobravo.com/for...and#post396954
The picture on post#47 explains what I meant about expansion joint vs vermicrete applied directly over the inner dome.