Question about insulatinng my door

[terdferguson]

I'd like to take my door that came with my fb casa 90 oven and add about 2" of ceramic board directly to the back for insulation. I saw one other guy do this but it seems like most everyone encases the insulating material by welding together metal. Is that necessary? What's the downside of not encasing in metal? Seems a lot easier to me and that part of the door isn't visible when the door is in place so not sure how much aesthetics matter here.

[fox]

I use vermiculite board a lot safer than using ceramic fibre!

[SableSprings]

For most people doing an insulated door, the concerns are durability & the balance between cost/bulk/efficiency. Ceramic board is easily damaged & can leave little "bits" of itself at the oven landing. Fox's firing (insulated) door works and looks great, but I'm sure he's very careful not to whack the open face of the board. Although I love the look of his door, I'm just too much of a klutz and had a stainless steel, insulation filled version made for my oven.

Having two doors is essential for me because I can't easily manage the weight of my firing door with one hand while loading bread dough in my oven...hence the lightweight cooking door. It appears that Fox is also of this same mind with his lighter weight door.

Have you looked through the "Show us your door" thread? Lots of ideas & discussion there.

[terdferguson]

Yeah I read through the entire show your door thread. I think the only person in there that did it this way was Fox. Fox, so the vermiculite board is sturdier? Less likely to break off little chunks than the ceramic board? If so, I'm having trouble finding vermiculite board on the internet. What's a good source to buy some?

[fox]

Virtually every wood burning modern stove is lined with Vermiculite so it should not be an issue to find,
I have found that a steel door backed with vermiculite last for years but yes of course it is prone to abrasion damage and you do need to be conscious about that fact.
It is a safe pruduct to use and won’t contaminate you or your food.
If you are not familiar with the product it is a bit like cork, is in fact compressed vermiculite and water glass mix,
Where I live it is available in sheet form and in individual bricks, a 2’x4’ sheet is around £55 ($70) and will do 3-6 doors depending on size so quite good value.
I have supplied many doors of different styles, a fully enclosed stainless steel door filled with ceramic fibre is quite an investment if you have to pay for a custom job. Mine cost around £250 to build.
They look great but still transfer heat out of the oven and can get very hot, the fist doors I made were cast from fondu cement and loose vermiculite at 4-1 pressed and compressed into a mould and that also worked very well but don’t last so long.
If you ever go to Italy you can see many doors made from oak, they are completely blackened and often smoking but seem very popular….
Second picture shows one of my early doors made in a mold, first lined with refractory cement then vermiculite 10-1 then more refractory