Finish over fire blanket

[chris_jones]

I'm in the process of curing my 36'' Pompeii oven and I'm contemplating how I want to waterproof/finish the oven. I've decided to do the curing before adding the fire blank and finish layer. My logic is that if something happens during the curing process or there is an issue with the oven construction, it will be easier to fix.

My plan is to use a 2'' layer of fire blanket, chicken wire, and then a layer of stucco. I've been reading that this might not be sufficient for waterproofing and some people have had mould issues with the fire blanket getting damp.

What is the best way to waterproof the exterior layer? Will I be ok if I finish with a masonry paint that is waterproof?

Thanks!

[david s]

Unfortunately, firing an uninsulated oven is risky as the difference between the inner temperature and the outside temperature leads to much greater thermal stress than if it were fired insulated. An example of this is a clay chimney that always cracks if it is uninsulated.
Regarding waterproofing the outer surface there are many ways to do it with many products available, but I think it’s best to forget about that step until the oven has had a fair amount of use and is totally dry. If a waterproofing layer is applied too early it can lead to blistering under it’s surface.