Insulating a mash tun

I have a gas fired RIMS setup, and lately I’ve been thinking about insulating my mash tun in order to save on fuel.
I know others out there do this, but I’m unclear as to what materials work best.
Anybody have any recommendations?

I made a slip on coozie out of an old foam yoga mat. Its rare that my temp drops enough that I need to hit the fire, but if I do I just remove the insulator and flame on. Mine isn’t rims, its direct fire.

I suppose I used the RIMS acronym incorrectly… My mash tun is also direct fired.  I just use a pump to recirculate during the mash, but it does have a PID controller that kicks the flame on automagically when the temp drops.

So ideally I’d like a material that I can leave on the whole time (and won’t burst into flames…).

A buddy made a jacket for his tun using a sheet of stainless and some “fireproof” insulation. I used quotes because some of the insulation around the valve did end up burning. I guess fireproof means ignition-proof in this case.

Sorry, no direct fire here. Just a schwag 10 g cooler that I wrap in a huge beach towel. Rarely lose 1degF over 60 minutes.

That being the case I think I would just buy gas. I think a miracle material would set you back more than a few gallons of propane

Same here. I wrap mine in a sleeping bag. Temp loss is ~ a dF, too.