Has anyone here fooled around with placing a piece of aluminum foil (or sometimng similar) under the base of a caldera cone?

I'd imagine that, in normal use, you lose a fair bit of heat into the ground. But if you put a piece of foil or some other reflective material under the base, this might not be the case. I wonder if you'd get shorter boil times and/or longer burn times.

What do you think? I might have to mess around with this.

I have used Aluminum Flashing under Essbit and Alcohol stoves with my windscreens to make the heat reflect up. I think it works great. Give it a try-can't hurt.

I really need to test this,but...
the bottom of the cone usually is almost cold whilst you cannot hold your hand at the top. So I figure that the heat loss at the bottom is minimal (?)
However, to avoid having the ground working as a heat sink, I would suggest putting some insulation under the stove in cold condition. I use a 3M kitchen scourer for that,(the green stuff) cause I have it with me anyway.
(you can see that in the "how to store the cone" thread)
Franco

MSR includes an eight inch dia. circle of foil with its foil windscreen kit.

I carry this foil disc to use under my Vargo Triad EX when I use ESBIT or FireLite fuel tabs and there is likely some benefit to it besides protecting the ground from heat if there is some unseen flammable stuff in the soil.

To me any efficiency is worth the small weight. I have put Gorrilla duct tape on the backside so the foil won't break through with repeated folding.

Eric