mineral wool mat, 660 Celsius?

[Freelance]

Hello,
as first layer insulation over the dome, i plan to use a fireproof mineral wool mat. Link to the tech sheet https://pim.knaufinsulation.com/file..._datasheet.pdf
Is this product suitable for such an application? Rated to withstand 660 celsius, is that OK?
It comes conveniently with a wire mesh which can be used for the second layer insulation with vermiculite/portland 10:1.
It's also quite affordable compared to other products.

[david s]

I went down this track a number of years ago as the mineral wool is a bit cheaper than ceramic fibre blanket and is only marginally poorer as an insulator. I built two ovens using the stuff, but have gone back to using ceramic fibre blanket. The reasons were that, firstly it does not cut as well. The ceramic fibre blanket is a dream to cut with a sharp knife and you can easily get quite precise cutting and filling of gaps. Because you need to fit the stuff over a compound curve, this is an important quality and saves a lot of labour and produces a far neater surface to work over. Secondly the stuff (at least the product I used) is not as dense as CFB and tends to compress easily. This quality also leads to issues when working over the top of the stuff, particularly when trying to build a 10:1 vermicrete vertically against the base of the dome. If building a dog kennel rather than an igloo this won’t matter much and could prove to be a better choice. Lastly, test I’ve done on the stuff show it is more water absorbent than CFB.