Esbit burner testing

[DAN-Y]

3 cups of 70 degree water or 35 degree water.  In a closed area or out in the environment?

 

Matt, I was outside at the time of the 7 tests. The temp outside was 50 degrees and the starting water temp was approx 55 degrees. There was a slight breeze.

Boiling 4 cups of water can be done with a single tablet of Esbit.  It will require an integrated, system solution which at the end o the day may not be worth the effort.  Still, it’s a fun experiment.  My 2 cents.

If I Use an aluminum K-Mart grease pot(modified with ridge) and my windscreen/pot support as an integrated system, I just might be able to do the 4 cups with one esbit. Is it worth it? sure it is…it’s all about stove science. as Yon has said: “the more you burn, the more you learn” :-)

[Bob Moulder]

Wading into the deeper end of Esbit esoterica and the magical 4-cup boil with one 14g tab….

I’d like to see it with 40°F water, ambient 50°F, no wind, 212°F on the thermometer. I’ve taken some pretty good cracks at it (I think the water was 42°F start temp) and have gotten up to 197°F IIRC.

Many times 3 cups with 1 tab—no mystery there.

 

[Jon Fong / Flat Cat Gear]

Bob,

Highly unlikely anyone would reach those goals (40 F water, 4 cups).  My calculations come up with an 83% efficiency requirement.  Increasing the starting water temperature to 70 F still requires a 68% efficiency.  My 2 cents

[David Noll]

I  used esbit for a long time and using my 1.3 ltr pot with a caldera cone it usually took about 1 1/2 tabs to boil 4 cups of water. One tab never got there while backpacking. I have no idea what the water temperature was.

[Bob Moulder]

David, that’s what I did (1.5 tab) when I was using a 1.3L pot.

Reliable boil every time in the field, where we really don’t want to be experimenting. ;^)

[DAN-Y]

I’ll go along with 70 degree starting temp. I can live with 68% efficiency ;) I have to wait till next week to do my tests. I’m on vacation down in Marble Falls, Tx  Twas 70 degrees down here….good weather to be testing :-))

[Eric Blumensaadt]

I have a 3 cup pot for my TD Caldera Cone Sidewinder. I’ll try some burns at that capacity and get times to 212 F. with a digital probe-type cooking thermometer.

I’ll do it outside and the temps will be in the 60s here in the ‘Vegas valley.

 

[DAN-Y]

Eric, you were my inspiration to search out 3 cup aluminum pot. The Toaks 900 is what I came up with. An aluminum one could not be found. TD sells them with a cone but didn’t need the cone.

[DAN-Y]

Using the BGET with bread pan corners and 1 regular size esbit, Kmart grease pot modified to have a ridge that is supported with a straight walled windscreen(fits inside the pot in vertical position) 4 cups water out of the tap, temp not known, air temp not known, raining outside, humidity is high. 3 test were done inside an enclosed, slightly heated, fish cleaning building here at the campground where I’m staying.  No boil was achieved only tons of fisheye bubbles on bottom of pot and lots of noise. It is my educated guess :-) that under ideal conditions, 70 degree air and water temps, calm conditions, 1 esbit will boil 4 cups of water with this set-up. I’ll do scientific tests when weather improves and I find my newly purchased digital thermometer.

It’s all in the interest of stove science :-)

[DAN-Y]

The power of esbit.

3 tests at 72 degree start temp. 58 degree air temp. calm conditions, 4 cups of water 1 regular esbit cube. Kmart grease pot.

1st test + no boil, water got to 209.9 degrees

2nd test = no boil, water got to 198.9 degrees

3rd test = no boil, water got to 210.2 degrees

Not too shabby for 1 esbit.

I used a Brian Green Esbit tray with bread pan corners to burn the esbit in.

Here is what the set-up looks like:

[James Marco]

Actually, all of the water would have been usable. I usually figure 190F as the cut off for “boiled” water. And I use 210F as the cut off to avoid temperature changes due to barometric pressure/altitude. Most of us do NOT live at sea-level.

Anyway, I also use a 34F as the starting point. This was about as cold as I could get water with ice cubes in it, figuring in the delay for filling the pot then lighting the stove. A fairly standard number that everyone can use.

[Bob Moulder]

I generally agree with 190°F as the ‘good enough’ cut-off, unless you’re boiling some very bad water for purification purposes. Other than that it’s more than hot enough for coffee or for rehydrating freeze-dried dinners.

However, 72°F is fairly high as start temps go (at least where I normally hike) and, as a very general and rough guide, 1°F can be subtracted off the top end for every 1°F lower for the start temp. Thus with a water start temp of 42°F, this set-up could be expected to heat the water up to about 180°F—i.e. about 210 minus 30 in real-world conditions out in the field… better IMO to use 1.5 tabs in that situation for a little cushion.

[Jerry Adams]

If you only heat water to 190 F, and let it sit for 1 minute, it’ll kill any bugs

for black tea, the water should get that hot

to dehydrate some foods, 212 F is better to get it better dehydrated, depends on the food though

[DAN-Y]

In this last testing I used the BGET, Brian Green Esbit Tray, to hold and burn the esbit cube. The wide bottom aluminum pot was my best choice of pot to absorb the esbits energy. The windscreen/pot support contained and distributed the energy to the base of the pot for increased efficiency.

In the above photo you can see the windscreen/pot support was placed on a large aluminum baking tray. Was it acting like a large heat sink, taking energy away from the BGET and pot support??? I suspect it was. If I were to do the test again on a wood surface, woold I be able to get the 4 cups to boil using the 1 esbit?   LOL…….the more I burn, the more I learn ;-)

[Matt Swider]

Interesting you should mention the aluminum tray being a heatsink.   After your first test above, I ran a qualitative test using two of my flatcat gear stoves, the epicurean and the FF 15.  Part of by stove setup is an aluminum disc, used to reflect heat from the burn chamber up to the pot.  But the tray containing the burning esbit sits directly on this disc.  Like you, I wondered if the disc was acting as heat dissipator, and removing heat from the esbit burn, causing a less efficient burn.

So I added 4 dabs of silicone to the bottom of the burn plate to somewhat thermally isolate if from the disc.  What if found was that the FF15 and the epicurean both had very clean burns, almost no residue left over afterwards.  I expected that from the FF15, but that has not always been my experience with the epicurean.  What I am not sure of is how much of that has been from slow burn mode with the epicurean, and how much (if any) was from a faster burn.  Need to run another experiment to find out , someday  . . .

[DAN-Y]

Matt, my experience with the BGET shows that if I cut the feet off and have it sit flat on a conductive surface there will be a significant slow down at the end of the burn and a small piece of esbit will remain when the flame goes out. A loss of energy is seen.

[Matt Swider]

I suspected as much Dan.  Glad you have the data to support my theory.  When you started reporting the results, I was thinking that a burner isolated like the BGET would have the advantage or running hotter.  I may thicken up the silicone dabs a bit to get a bit more space.

My experience with the epicurean is that the esbit melts and stays stuck to the plate when in simmer mode.  I would like to see if this isolation will prevent that from happening.  Likely when I have time over the Christmas break I will run some more tests.

[DAN-Y]

When the esbit melts inside a BGET, the bread pan corners prevent loss of the melt and the high heat burns that melt completely. All that is left is a very lightweight ash. The only other burner I’ve seen in this thread that burns the esbit completely is on the first page(Richard May). It’s the bottom of a redbull can. The smaller the pop can to the size of the esbit, the better. The concave shape concentrates the melt close to the central flame.

[DAN-Y]

I bumped this thread up for those wanting more info on esbit testing with the BGET style burner.

[DAN-Y]

I’ve been able to create  a titanium BGET esbit stove with integrated titanium pot support. Works really nice, better than I expected. I made it to use 4 gram esbit to heat 1 cup of water in an aluminum cup. I did some tests with a full size esbit cube using a Toaks Light 700 pot with cone windscreen and was able to boil 3 cups easily with 2 min extended boil. I’ll do more test with that tomorrow.

 

I did 3 tests with starting water temp at 74 degrees, calm conditions in my garage. Esbit burns complete, nothing remaining. Esbit tray is 1/8″ above the ground.

1. = 178 degrees
2.  = 184 degrees
3. = 189 degrees.

[Matthew / BPL]

I like where you are going with this.

[Bob Moulder]

Very nice.

Weighs about 8-10g?

I lust for your spot welder, lol. :^)

 

[DAN-Y]

Yes, it weighs in at 8 grams. I’m going to make another one today. It needs an adjustment in air intake holes and positioning of the esbit tray in relation to the air intake. Little things can make a big difference in efficiency. I’m watching the burn by having the stove on a sheet of tempered glass overhanging my work bench. I use a hand held, 12×12″ plastic mirror under the glass so I can see all around the stove while it’s inside the cone enclosure.

Ever since we started posting the test results in this thread I’ve been interested in the amount of energy in esbit and the method we use to capture that energy. 3 cups of water with one cube is impressive. I should be able to 3.5 cups by using a Toaks 900 pot or a Kmart grease pot.

The diameter of the stove was determined by the ridges/indention’s on the bottom of the aluminum can. It’s very stable with one cup of water in it. I’ll try and get more tests in by the end of the day.

 

[Bob Moulder]

As discussed before, very subjective depending upon water starting temperature.

I like to start with “cool mountain stream” temperature of something like 50°F, and even at this temp I have boiled (full, rolling boil) 3 cups with one 14g cube.

But even at 70°F start temp I would still say that 4 cups (our own little Holy Grail) is out of reach and 3.5 cups is possible. Although 4 ‘heated’ cups is usually adequate in the field.

I myself am now a 2-cup guy so I am on easy street regards to boiling water, although I’ve had to give up my cigars and JD and greatly reduce coffee consumption on advice of my gastroenterologist…. things I should be doing anyway…. sigh.  :^/

[DAN-Y]

I did not make a modified stove today but did take some time to do 3 tests.
I heated 4 cups of water to 178, 184 and 188 degrees in 3 tests using a kmart/stanco grease pot and a straight wall, aluminum windscreen that was held 1/8″ from side of pot and extended 1″ above pot. I used one, 14 gram esbit and my new Ti esbit stove which has an Ti BGET integrated into it. Starting water temp was approx 71-72 degrees I could not find my Ti Cone for grease pot. I think if I were to use one I could achieve 200+ degrees with one esbit cube. The cone touching the sides of the pot add a good amount of heat to it.
4 cups heated to those temps is ok in my book :-)
The ability of the BGET to burn the esbit completely is the reason for getting the high temps. Then comes the windscreen to help capture the heat.</div>

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