Sterno Inferno model 70138 High-tech Sterno?

[Bob Moulder]

I haven’t forgotten it! Admittedly I’ve been distracted by hammocks the last few weeks, although when we’ve gotten some decent cold it has also been accompanied by howling wind and then a quick warm-up. This morning would be nice (30 deg and very light wind in the “lab” 😀) but family visiting for the holiday might find it a bit strange.

[DAN-Y]

Then there’s the issue of you buying my soot-ridden Inferno pot. You won’t be able to afford it, Dan. You see, it is destined to become a collector’s item, and it likely will soon be inducted into the Crappy Stove Pot Hall of Fame.

Gary is right, his opinion of the Crappy Stove Pot is formed :-)  Will the cozy-no cozy results make a difference?  Bob’s results will be the last word :-)

[Gary Dunckel]

And your results will be the penultimate word, Dan, so don’t let us down.

But actually that pot isn’t totally crappy – I’ve found a good use for it outside the alcohol-burning arena. I’ve modified a Fire Maple FMS-300T stove by bending the support arms such that they fit nicely between the HX fins of the pot. This concept was Josh Leavitt’s original idea for the BRS-3000T stove,  until I learned that it positioned the burner head too close to the pot’s bottom. That was when I devised the pot riser disk (the Thingy) to solve things (I passed that concept on to Josh, to freely use for his own purposes). It just happens that the FMS-300T works perfectly with the Inferno pot without using a riser disk. I have to fiddle a bit with the support arms to get them inside the HX fins, but it works great. This is an ounce lighter than a Jetboil Sol/BRS-3000T setup, packs up more concisely, and it looks cool with the cozy on it. It will be good for having my morning Via outside while motel camping or crashing at my buddy’s mountain place.

Today’s the day to score a bunch of those Costco down throws for me and my friends to modify into warm weather quilts. They’re on sale for 4 days at $16 each – what a sweet deal! I’ve got to get into the shower now so I can be first in line when Costco opens.

How do you like my thread-drift so far?

[DAN-Y]

1st test “with cozy”. 2 cups water starting temp was 53 degrees, air temp at 56 degrees, 15ml of denatured alcohol poured into empty Starlyte XL3. At flame out water temp was at 203 degrees

2nd test “no cozy” 2 cups water starting temp was 54 degrees, air temp was 57 degrees, 15ml of denatured alcohol poured into empty Starlyte XL3. At flame out water temp was at 208 degrees.

Cozy seems to be insulating pot from heat rising up along side of pot.

Will do 2 more tests this evening after sun sets so I can see the flames inside the pot support…..it’s a stove testers thing, gotta see the dancing flames 

[Gary Dunckel]

Good work, Dan. So what were the total burn times with 15 cc of alcohol? Wasn’t Bob getting a boil with 1/2 oz of alcohol? Thant’s about 15 cc of fuel if I recall correctly. The altitude in MS and NY should be about the same, so that wouldn’t be much of a factor. I wonder why you weren’t quite able to get a boil. Let’s keep on this, to see how we can get a boil somehow using just 15 cc of alcohol. The only other variable I can imagine is the stove-to-pot distance. And perhaps the brand of alcohol used.

[DAN-Y]

These tests are for cozy, no cozy. Not interested in time.

If starting water temp was at 70 degrees, a boil would have been achieved.

At this point, the burner, pot support and pot is considered a “good” set-up. The lid I used today was a DIY one made from thanksgiving strawberry rhubarb aluminum pie plate. Needing a lid was a good reason for me to finish off the pie 

Todays set-up

[DAN-Y]

3rd test “with cozy”. 2 cups water starting temp was 53 degrees, air temp at 59 degrees, 15ml of denatured alcohol poured into empty Starlyte XL3. At flame out water temp was at 198 degrees

4th test “no cozy” 2 cups water starting temp was 52 degrees, air temp was 58 degrees, 15ml of denatured alcohol poured into empty Starlyte XL3. At flame out water temp was at 198 degrees.

[Roger Caffin]

Does this suggest that any small loss of heating due to the cozy keeping the flames away from the side of the pot is easily matched by a slight loss of cooling due to the presence of the cozy?

Cheers

[Bob Moulder]

I am guessing that when the ambient temperature is much colder it will warm a bit quicker with the cozy, and that at all cooler and cold temperatures the water will retain heat longer after boiling. This is why I’ve been waiting for a nice, cold day, and my plan is to keep tracking the temps after the flame is out.

[James Marco]

I agree. At around 50F, I am guessing that the cozy helps heating with a small alky burner. I noticed this some time ago. But, since most of my camping is above 32F, it makes only about a 2-3 degree difference. I also believe (with nothing like scientific testing) that using the cozy after boiling is manditory to maintaining warm water. I usually just drop my hat(felt) over my water most mornings (wearing my sleeping beanie.)

[DAN-Y]

Let’s keep in mind what the koozie aka cozy was designed for and apply it to what we are discussing here. The sides of the pot are insulated during the heating process, preventing hot outside air from entering through the walls of the pot to the cold water inside.

From “the web”:

Koozies are used to insulate a chilled beverage from warming by conduction and heat radiation, like a hand, warm air, warm surface, or sunlight. Using a koozie can reduce the rate a drink warms in the sun by up to 50%

[Gary Dunckel]

Dan, I can’t believe that you are actually using that god-awful-damn-heavy red stock Inferno pot stand, and also that you actually drink Mountain Dew. Nonetheless, what I am really wanting for you to measure is how long does 1/2 oz of alcohol burn in the XL-3 until burn-out. If you do that I will offer an apology about the Mountain Dew comment…

[DAN-Y]

Gary, next test I will do a timed study. Diet Mt Dew has yummy citrus juices and no sugary after taste.

5th test “with cozy”. 2 cups water starting temp was 61 degrees, air temp at 66 degrees, 15ml of denatured alcohol poured into empty Starlyte XL3. At flame out water temp was at 199 degrees

6th test “no cozy” 2 cups water starting temp was 61 degrees, air temp was 66 degrees, 15ml of denatured alcohol poured into empty Starlyte XL3. At flame out water temp was at 210 degrees.

Gary, using the heavy red pot support shows everyone that great results can be had with a stock Inferno kit with slight modification to lid/cover.

An interesting thing that I learned was 1/2 ounce of fuel can be put into a large burner(Starlyte XL3) that could hold 3+ ounces of fuel and still be efficient.

As we all know, pasteurization occurs at 170 degrees and so we have seen by my tests of the Inferno, safe water can be had with 1/2 ounce of denatured(meths) alcohol.

Interesting that Sterno would venture out and use the heat exchange fin technology to be used with alcohol. Thank you Sterno 

Now as far as Gary goes, he’s in the fast lane along side all the canister users.

And Yes, the cozy prevents loss of heat once the pot is removed from the stove

 

 

[Gary Dunckel]

But we still don’t know <span style=”text-decoration: underline;”>how long</span> the stove burns with 1/2 oz. of alcohol, Dan. Guess I’ll just have to find out for myself, huh? But we still know that Mountain Dew has loads of caffeine, which isn’t good for kids under the age of 4, or small pets. Probably OK for consenting adult patio stove testers though, in reasonable quantities.

But what have we learned so far – that a cozy has no true effect on the speed of boil, but that it slows the water cooling after the boiling is done? Hopefully, Bob will provide us with the facts here.

I don’t like to test when ambient is over +50* F, or the starting water temp above that either. Those aren’t real world conditions where I hike. The next few days might allow me to get back to testing this stuff though. But I won’t be using that heavy stock red Inferno pot stand, you can can bet on it…

However, let’s be clear, Dan, I do like to achieve a 2-cup boil in a short amount of time, but if the XL-3 can do a decent boil with 1/2 oz. of alcohol, I’m all for it. But I haven’t seen any indication that it’s going to be a reality. My take on the XL-3 is that it takes 20% longer to achieve a 2-cup boil, but that it burns 50% longer with a given amount of fuel. So it might be best used (by me) for slower simmering, but not for speed boiling. My question now is whether one can get a true 2-cup boil with 1/2 oz. of fuel in a reasonable amount of time, something that hasn’t been demonstrated thus far. Maybe Bob can refute this with his upcoming testing results. We’ll see…

[Gary Dunckel]

We still don’t know how long the stove burns with 1/2 oz. of alcohol, Dan. Guess I’ll just have to find out for myself, huh? But we still know that Mountain Dew has loads of caffeine, which isn’t good for kids under the age of 4, or small pets. Probably OK for consenting adult patio stove testers though, in reasonable quantities.

What have we learned so far – that a cozy has no true effect on the speed of boil, but that it slows the water cooling after the boiling is done? Hopefully, Bob will provide us with the facts here.

I don’t like to test when ambient is over +50* F, or the starting water temp above that either. Those aren’t real world conditions where I hike. The next few days might allow me to get back to testing this stuff though. But I won’t be using that heavy stock red Inferno pot stand, you can can bet on it…

However, let’s be clear, Dan, I do like to achieve a 2-cup boil in a short amount of time, but if the XL-3 can do a decent boil with 1/2 oz. of alcohol, I’m all for it. But I haven’t seen any indication that it’s going to be a reality. My take on the XL-3 is that it takes 20% longer to achieve a 2-cup boil, but that it burns 50% longer with a given amount of fuel. So it might be best used (by me) for slower simmering, but not for speed boiling. My question now is whether one can get a true 2-cup boil with 1/2 oz. of fuel in a reasonable amount of time, something that hasn’t been demonstrated thus far. Maybe Bob can refute this with his upcoming testing results. We’ll see…

[Bob Moulder]

Gary, somewhere upthread when I was testing for max fuel efficiency, the boil times were in the range of 8 min to 8:30 min, with water and (especially!) ambient temps above 50°F however.

I used this set-up on a short trip (hammock tweaking!) a couple of nights ago (and yesterday morning for breakfast) with ambient and water temps of 46°F (evening, light breeze) and 38°F (morning, with a stiff breeze of about 20 mph, using a log for a natural wind break) and found the boil times to be acceptable.

“Acceptable” is quite an ambiguous term, of course, but my habit is to busy myself with other things while the water is heating, which always results in a before-you-know-it impression when it comes to boil time. Although my watch has a superb stopwatch function which could easily be employed to add a skosh of scientific rigor to the exercise, my mind was preoccupied with the angle of the hangle, and the Sterno setup has become a trusted piece of kit that I simply use and don’t think about so much these days.

I am still awaiting a genuine polar vortex in order to do some colder testing. The forecast here for the next 10 days predicts barely below freezing for overnight temperatures, although tonight is forecast for 26°F so maybe I will get everything prepared and do a test early tomorrow morning. It will involve both stoves running simultaneously with a thermometer for each, and a time lapse video of the proceeding, so a bit of a production.

Right now it’s 37°F on the deck, ugh!   :^/

[DAN-Y]

Aug 13, 2017 at 7:00 am Bob Moulder wrote:

Now here’s some interesting stuff after doing some test boils this morning with my Sterno set up using the Starlyte XL3 (got it yesterday, Dan — thanks!).

I wanted to see if I could put just 20ml of DA in it and get a boil, as per above. Got a boil in about 9:15 and continued to boil another 1:30 or so.

Next came 3 boils which were done after filling the XL with approx 90ml of DA. Weight of XL plus fuel, but not cap, was 83.6g. (rough test, generic conditions)

First boil in 9:15, weight after boil 72.5g, with 11.1g (approx 14ml) fuel consumed.
Second in 8:45, weight after boil 59.9g, with 12.6g (approx 15.8ml) fuel consumed (rather breezy during this boil).
Third boil in 8:00, post-boil weight 48.3g, with 11.6g (approx 14.5ml) fuel consumed.
Pretty darn fuel efficient! 1/2 fl oz to boil 2 cups is close to the limit of what can be done with alcohol.

[Gary Dunckel]

OK, Dan, yesterday afternoon I did a test of using 15 cc of regular Klean Strip DA (not the Green version). The problem was that we had a record-setting warm November day (81* F!). It was 70* F in the late afternoon, and the water was the same temperature. I didn’t quite get a boil, and the flame went out at about 12:30 minutes. The water got to 195* F (it boils at 201* F at my 5440′ altitude).

So it doesn’t appear that I can achieve a 2-cup boil using just 15 cc of alcohol (based upon this one test). The conditions were perfect for getting it done – warm air and water, no breeze. The XL-3 does seem to be a slow burner, however, and it should work well for doing a simmer (or maybe for melting snow, since it has a 3-oz. capacity?).

One thing I should tell you is that the copper ‘wick’ snapped off. Not sure why, as it had only been lit maybe 15-20 times, and I never used the cap which would have bent the wick down. The wick isn’t really needed, as the stove lights fine without it. But it was so damned cute and unique. A pity…

[Bob Moulder]

I did some pretty good tests this morning, ambient temp 26-29°F, no wind.

Although I had intended to run both setups at the same time and do a time-lapse video, it turned out that one of my digital kitchen thermometers was about 5°F off, which made for an annoying discrepancy right out of the gate. So I decided to do it the old-fashioned way and do two well-controlled runs and eliminate as many variables as possible.

I was not testing for fuel efficiency, but I made sure the burner had the same amount of fuel in it before starting each run, and lit the burner and let it go for 3 minutes to thoroughly warm up because I noted in some earlier tests that the starting condition of the stove (temperature and amount of fuel) can affect heat output somewhat.

Ambient for No-Cozy was 29°F, water 40°F start temp. Cozy ambient 26°F, water 37°F.

Test setup

Conclusions: As I had guessed, there was a slight advantage with the cozy in the heating phase and a definite—although not huge—advantage for the cozy during the cooling phase. Despite starting off with a 3° disadvantage, the pot with cozy “caught up” and achieved a lid-knocking boil in 10:20 compared with 10:09 for the non-cozy pot. After the flame was put out, however, the cozy setup remained 10 degrees warmer than the non-cozy some 12 minutes later. I actually expected perhaps a bigger difference, but it am what it am.    ;^)

Data sheets side-by-side

What is interesting is that I decided to see how long it took the cozy setup to reach 171°F in the cooling phase. I did absolutely nothing to disturb the setup and if you look at the bottom you can see that between 23:30 and 27:48 the cozy version dropped 10°F in 4 minutes and 18 seconds, which surprised me. Hmm….

[Gary Dunckel]

Good work, Bob. Your results roughly parallel the ones I observed with my 3 tests. However, our parameters and ambient conditions differed. I was forced to measure the cooling rate at air temperatures of 60-70* F (I did this last summer). I measured the cooling water temperatures every 5 minutes for both the cozy and the non-cozy. The biggest water temperature drop occurred in the first 5 minutes, going from the boiling temperature of 201* F to 188* F with the cozy and 179* F without the cozy. After that first 5 minutes, they both dropped roughly 10* F every 5 minutes thereafter. After 30 minutes, the cozy water was 143* F, and that of the non-cozy was 133* F. So in the 30 minutes, the cozy water cooled by 58* F, which was an average rate of 1.93 degrees/minute; for the non-cozy the water cooled 68* in 30 minutes, for a cooling rate of 2.6 degrees/minute. So the cozy provided ~ 25% less cooling. And as you learned, the use of a pot cozy doesn’t seem to overmuch affect how fast the water boils.

I was confused as to if the water actually got hotter after burnout in your tests. Was that true, and if so, why so?

 

[DAN-Y]

I used the Inferno pot and pot support with the Starlyte XL3 burner

Did 3 tests with burner filled with 80 ml of denatured alchohol at beginning of tests. No fuel added while tests were under way.

Used a thin silicone disc as a snuffer to snuff burner out as soon as boil was achieved. Disc was on burner when weighed for fuel usage. Disc prevents loss of fuel while burner cools.

Fuel usage was measured by weight using digital kitchen scale. 1st test was measured by ounces but 2nd test was switched to grams because of weight of fuel used was said to be 1/4oz.

Pot and burner were cooled to air temp prior to every test.

1st test, burner weight, 3oz. at begining of test. Water temp at start 64 degrees, air temp 67 degrees. Time to reach boil 10 min. Burner weight at end of test 2-1/2oz. fuel used 1/2 oz.

2nd test, burner weight, 2-1/2 oz. at beginning of test. Water temp at start 64 degrees, air temp 64 degrees. Time to reach boil 11 min. Weight of burner at end of test 2-1/4 oz.(62 grams) 1/4 ounce fuel used.

3rd test, burner weight, 62 grams at beginning of test. Water temp at start 62 degrees, air temp 62 degrees. Time to reach boil 10 min. Weight of burner at end of test 51 grams. 11 grams of fuel used.

[Bob Moulder]

I was confused as to if the water actually got hotter after burnout in your tests. Was that true, and if so, why so?

Good catch, Gary! That was an interesting phenomenon.

I had to pick up the pot quickly to blow out the flame and I speculate that this physical agitation of the water caused the release of a bit more energy, similar to the way that shaking a cold fuel canister causes the vaporization of a few molecules of the compressed liquid gas. At one point the temperature bumped up to 213°F between 10:00 and 10:30 as I was moving the pot.

At any rate, I wrote down the numbers as they appeared at the precise time intervals. I considered making a graph of the data points but IMO the difference isn’t stark enough to warrant the effort.

The results might be more dramatic at 0°F. However at that temperature I’m not going to be using alcohol anyway because IMHO it simply isn’t the right tool for the job.

There are also other variables to test if one is so inclined, such as performance difference with wind or when using a non-HX pot. We don’t often think about it, but when the heat is removed from a HX pot the fins actually work in reverse, cooling the pot more quickly. And of course there are a bunch more variables such as pot shape, windscreen type, dimensions, etc.

All said and done, I have used this system quite a bit in the field and it has become my go-to alcohol setup. Not the lightest in weight (although certainly not heavy!), but the most fuel efficient and hassle free, pretty darn good in the wind and fast-enough boil times. And the handles don’t get hot. ;^)

 

[Jon Fong / Flat Cat Gear]

I was confused as to if the water actually got hotter after burnout in your tests. Was that true, and if so, why so?

The thermometer accurately reads the water temperature, the issue is that when heating water, the water itself is not always a uniform temperature.  When the water reaches a full boil, there will be a lot of mixing due to the rising air bubbles and at that time, the thermometer reading is representative of the bulk water temperature,  My 2 cents

 

[Gary Dunckel]

That’s a good explanation, Jon. It makes sense.

So Bob, are you able to get a full boil using .5 oz (~ 14 ml) of fuel? If so, methinks there must be elves in your NY forests that cast out benevolent vibes on your behalf. And… what is your total burn time with that amount of alcohol? This is all I need to know about the Inferno/XL-3 performance. Once I learn these 2 things, I can move on to some other geek project, like plotting a shorter route to India or something.

 

[Gary Dunckel]

I just now did one other test with the Inferno, this time using Dan’s Starlyte burner. 15 cc of DA, 2 cups of 60* F water, and 70* F ambient air with zero breeze. The water only got up to 185* F, and I am guessing that flame-out was around 9 minutes. I couldn’t really tell, as the sun was shining brightly on the stove/pot. Anyway, in my hands, there’s no way that I will achieve a 2-cup boil with just 1/2 oz. of alcohol, regardless of which stove I would use.

The good part of this test was to note the cooling rate of the water while employing the cozy. Over 15 minutes the water temperature dropped from 185* F to 170* F, which happened to be a steady 1* F each minute. This about half as fast at the 1.93 degrees/minute that I had reported above. I attribute this in part due to to the 70* F day, but mainly because it is a brilliant blue sky with radiating Colorado sunshine blasting the side of the black pot cozy. Pot cozy for the win!

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