This is an odd time to be posting this, but the post in the gear forum on water bottle koozies got me on the subject.
This is a homemade, deluxe water bottle insulator that I use for winter camping. I store a 40 oz stainless steel Klean Kanteen bottle inside of it, carried on the sled during travel or stashed somewhere overnight (I'm a cold tenter), so that I have water ready to go when I get to camp or first thing in the morning.
The thing that makes it unique is the insulation material, which is a chunk of large-diameter pipe insulation from McMaster-Carr (item number 4463K176). It's 3/4" thick, seamless, and the inside diameter (with some metal foil adhered to it for heat reflection and friction reduction) is a perfect slip fit for the Klean Kanteen bottle. I got carried away and added a tethered lid with pull-out loop as well. It fits perfectly inside my therm-a-rest stuff sack (which is available since I don't bring inflatable pads on winter trips), and then crosswise inside a milk crate, in which I carry miscellaneous stuff on the sled.
I still have a couple of feet of the pipe insulation I could spare if anyone is interested.
How long 'til freeze-up?
Bruce