Originally Posted by
Western Flyer
My stove certainly is “heat limited” and thank God it is. I would say a better and more accurate description in terms of its intended use would be “heat sufficient.” I don’t need the BTU output of my Cajun Classic I use for crab boils and corn feeds at summer picnics to stir fry a few vegetables or steam a potato when solo touring. Or to make a one person paella for that matter. I can burn my morning oatmeal quite quickly if I don’t pay attention and turn the flame down to simmer.
I had a look at your Wikipedia links for heat and temperature and I think at a layperson’s level I can grasp the difference. Perhaps I didn’t describe the fiberglass clearly enough. It was a 4 oz per sq yd open filamented stranded woven glass cloth. The type of fiberglass that in this case was saturated with epoxy resin to cover a wooden kayak to protect the plywood when landing of a beach and the like. So the cloth is designed to “wet out” (be penetrated) quickly and completely with the relatively thick epoxy. So as I see it, regardless of the insulating properties of aluminum, steel and glass, the glass cloth allowed more heat (if I am using the term correctly) to reach the bottom of the pot and it did so while dispersing the heat more evenly over the pot’s bottom.
“When a path permeable only to heat is open between two bodies, energy always flows spontaneously as heat from a hotter body to a colder one.” What I think is missing in this Wiki definition for this situation is that the path has to be uniform and it is not when a typical camping pot with a banged up distorted bottom is placed on a flat metal sheet. On the other hand the pan is not dependent on contact with the glass cloth or the thermal conductance (new words for me) through the glass filaments themselves for heat to reach it. The flame, hot gasses or whatever the correct term is flows through the cloth touching the pot directly, but in a restricted manner. I have sourced a stainless steel cloth that might act in a similar manner to the fiberglass and would certainly be a lot more durable and I am sure could withstand the heat output of a canister camp stove. Stay tune and I will report back.
Let's leave the heat output alone.
If I am understanding your description of the fiberglass, you have a square of open weave fiberglass that is impregnated with an epoxy resin. I'm supposing that because the cloth wouldn't have any kind of rigidity. Let's start with the fiberglass. Fiber glass has a t
hermal conductivity of 0.04 W/mK. In real speak, that's damned low. Not much heat gets through it. Aluminum, on the other hand has a thermal conductivity of 205 W/mK or about 5000 times as much. Add in the epoxy and you have a pretty good pad to keep the heat from ever reaching the pot.
You also have to take into account that the epoxy is an organic based molecule that isn't all that heat resistant...some are but I doubt the one use for canoe repair is. It will start to pyrolyze at around 250 C (480 F). In practical terms that means it will start to stink. And then it will start to burn. And that would be bad. I would suggest that you test this stuff outside.
Now it is true that heat
always, always, always flows from a hot body to the colder body. But it doesn't have to flow fast. With something like fiberglass, the rate at which the heat flows...the watts/meters* kelvin above...is very slow. That's the point. If the thermal conductivity is low, the substance is an insulator. The shape of the object makes little difference but the substance of the object does. In this case, the fiberglass won't act to speed the conductance of the heat from the flame to the pot but will act to slow it down and divert it. If you stop and think about this, there is a reason that we use fiberglass for insulation in our attics. It doesn't conduct heat very well. You could use your resin impregnated fiberglass cloth as a trivet because it will insulate real well. But you can't use it to enhance heat flow.
I'm not sure why people are looking for any kind of enhancement to conducting the heat from the stove to the pot in the first place. Anything stuck between the pot and the fire is going to require heat, i.e. stove energy, i.e. fuel, to heat it up. The aluminum of the pot will do a very admirable job of transferring the heat from the stove to the contents of the pot (sorry, but titanium isn't as good as aluminum no matter how much more you paid for the titanium
). The thinness of the aluminum is going to ensure that the heat moves quickly through it and not much of the heat is going to be wasted on heating up the metal of the pot.