Insulation Efficiency

[TDVT]

Thanks Jim. Not having seen the product, I was thinking it was maybe less dense than it actually is.
My inclination is to use a box enclosure around the oven. Have you ever used unfaced fiberglass at the point you would use vermiculite fill (after a hi-temp blanket)?
I think it has better insulating properties & is certainly easy to get.

Ted

[CanuckJim]

Ted,

I have no experience with using fiberglass insulation around an oven. What I normally do is use three inches (five at the apex) of insulating blanket, then a further three (and five) of castable refractory insulator. The product I use for this last is called Matrilite 18, although you could use vermiculite/cement at a ratio of 5:1. After that, you could fill with dry vermic, but I really don't think it's necessary, even in my climate.

Jim

[david s]

I used fibreglass insulation on my first oven. It works ok but compresses easily which made it really hard to get the outer spherical form right. I ended up with only half the intended insulation thickness. I would only use vermiculite again. There is a cloud over the safety of ceramic fibre (carcinogen)