After some feedback on my build thus far

[ChrisNazareth]

Thanks David
I was thinking of fabricating a stainless coller around the flue. 5 or 10 mm larger and fill the gap wit high temp silicon.
However I think the cardboard is a better/easier option.
Do you think there is any value in coating the perlite layer with Boncrete water solution to help the render stick better?

[david s]

Thanks David
I was thinking of fabricating a stainless coller around the flue. 5 or 10 mm larger and fill the gap wit high temp silicon.
However I think the cardboard is a better/easier option.
Do you think there is any value in coating the perlite layer with Boncrete water solution to help the render stick better?

No not really because it is likely to pull some of the grains off the surface. If you wrap the oven up well it holds the moisture in the render layer quite well

[ChrisNazareth]

Thanks David
will post an update when done.
regards Chris