In my blog last week about a field test high on Mount Shasta, I revealed some gear performance inadequacies, including a mention of the Jetboil stove and its propensity to puff plumes of un-ignitable vapory gas in cold conditions.
Here’s the just of the situation, as quoted from my first blog posting:
“Plumes of vapory gas puffed benignly out of this stove when I tried to light it up at 10,500 feet to cook some soup. Though it was only about 20 degrees out, the stove would not work. My solution: Huddle in my sleeping bag, stove clutched between my thighs, for a 1/2 hour. Mind you, it wasn’t the canister that was frozen, as I’d climbed with that next to my body to keep it warm. The actual stove unit was too cold to operate. I was kind of dismayed with this, though after warming the unit up in the sleeping bag it fired and cooked the soup in no time flat.”
According to David Eckels and Chris Lathrop, respectively a product manager and a sales/marketing VP at Jetboil Inc, the stove’s built-in piezoelectric sparker was to blame. Had I used a match or cigarette lighter to ignite it, the plumes of vapor would have fired up. But the tiny spark generated by the piezoelectric igniter is not intense enough to light the vapor that came about because of a cold valve in the stove.
Here’s the full explanation, in formal letter form, from the boys in the Jetboil lab:
Thanks for sharing your experiences with us late last week. We really value learning from extreme use of our products, and feedback such as yours is key to this process. Below we have summarized our findings as you requested during our conversation.
Findings In summary:
You described observing a cloud of fuel that your piezoelectric igniter would not ignite when using a canister warmed by your body, and a cold Jetboil burner kept in your pack. We were able to duplicate this experience in the lab, both with the Jetboil burner, and with several other canister stoves in our possession. It seems that as warm vapor gas passes through the very cold valve and burner it cools and condenses to a liquid. The canister pressure forces this liquid through the orifice, atomizing it into tiny droplets. These droplets are much harder to ignite than vapor, and a piezoelectric spark may not light them. We were able to start all the stoves tested with a butane lighter or match, both of which are much more concentrated heat sources than the piezo can produce. All the stoves we tested would flare briefly upon ignition, as the liquid burned off, but the flame would settle rapidly as the stove temperature increased. It appears that this issue is not related to altitude, but rather very cold temperatures.
Once again thanks for your input, and please contact us if you have further questions.
David Eckels and Chris Lathrop
Outdoor Product Manager, VP Sales and Marketing
540 North Commercial Street | Manchester, NH 03101 USA
tel 603.518.1600 ×204 | dir 603.518.1608 | fax 603.518.1619