questions about materials for insulating my BIAB mashtun/kettle?

[cmybeer]

As a northern BIABer one thing I struggle with is maintaining temp in the winter months (yes, I'm already worried about that...). I don't want to carry my kettle inside and out, don't want to do electric recirculation, and don't want to do some ghetto bungy chord blanket wrap (no offense if that's your style, whatever works right?).

So, that said I want to make a customized kettle wrap that is insulated, heat resistant and fire retardant. I'm planning on essentially making a jacket using an insulator on the inside covered front and back with a heat resistant (possibly water proof because we're brewing) fabric. I plan on having it sewn together with cutouts for my equipment with either valcro or zippers to hold it together. I'm have a friend that can do it but am looking for material ideas.

So any suggestions for what goes inside to help insulate and keep it warm?
Any suggestions on what goes outside that can butt up against the kettle and face the elements? Bonus points if it can be used while the burner is being fired.

 

[cmybeer]

Just to give you an idea of what I'm thinking I found this 1" thick insulwool ceramic fiber fire ratardant blanket insulation and was thinking that something like that would make a good inner material to build around. Don't know the R-value or how well it insulates but it fits the general idea.

When I googled fireproof fabrics these canvas and vinyls were the first thing to come up and are along the idea of what I was thinking.

Anyone have other suggestions? Critiques? Further ideas? What do you look for in mashtun insulation.

 

[OneInTheHand]

Roxul?