Jon, I had a similar experience when I tried to use an alcohol stove with a Jetboil. Back a few years ago when we were raging about the BRS-3000T stove and the pot riser disk combination, I think it was Ryan Jordan that asked if anyone had tried alcohol stoves with a JB pot. That stuck in my head, so I tried it last fall. I tried several stove-to-pot distances and nothing worked worth a hoot. I think in one try the flame was being starved of oxygen, so I increased the stove to pot distance to maybe 1.5″. That never quite got a boil, although the flame wasn’t quenched. But it did dance around, and when it started to melt the cozy I blew it off. Perhaps a better operator than me can make it work, but I’ll stick with the BRS-3000T and riser disk thingy.
Today I tested the FMS-300T stove/riser disk with the Sterno pot and cozy. It worked OK, but not quite as well as the BRS-3000T with the Jetboil cup. On a 71* F day (in the shade), it boiled 2 C of 45* F water in 6 minutes at a medium-low flame setting, using 5.1 grams of canister fuel. This was just a slight bit more fuel and maybe a minute longer than the BRS-3000T.
And to appease Bob, I also did a comparison test to see how fast the boiled water would cool with the cozy vs. no cozy. It was in the low 70* F temperatures, so it isn’t too pertinent to cold weather conditions. However, the results were interesting, if not very dramatic. So here’s what I did…
My first 2-cup boil was done by using a can of generic ‘Sterno-like’ gelled chafing fuel with the stock Sterno Inferno setup + the pot with the cozy. That sucked, as it took a full 18 minutes to achieve a boil, which happens at 200* F at my 5440′ patio altitude. I might buy some actual Sterno fuel to see if that works, but I’m not very optimistic. I used a digital kitchen thermometer to plot the cooling rate. I then boiled water with my FMS-300T/ riser disk and the Sterno pot without the cozy. After boiling this second time I placed the pot back on the stock Sterno Inferno “stove/windscreen” to standardize the cooling environment. I should note that during the first test, with the cozy, ambient was 71* F, whereas it had warmed up slightly to 74* F for the second test (without the cozy). This might have a slight influence on the results.
The results:
At 15 minutes of cooling, the water temperature with the cozy was 172* F; without the cozy it was 154* F.
At 20 minutes: cozy – 164* F; no cozy – 150* F
At 30 minutes: cozy – 150* F; no cozy – 135* F
At 40 minutes: cozy – 136 * F; no cozy – 125* F
So it appears that the use of a cozy is more important for retaining heat early on, for the first 10-15 minutes. This is likely when we most want to keep the water warm-to-hot, such as for making a hot drink after the water has been added to the FD meal. As we get to the 40-minute mark the difference is less dramatic. I plan to do this test again when the ambient temperatures drop down below freezing. That will be more telling about the heat retention efficiency of a 3 mm. neoprene cozy.