Esbit burner testing

[Dan Yeruski]

Aaron, is your comment correct, can your BGET style holder that fits a 14 gram esbit cut in half easily boil 2 cups of the coldest water in a stream you can find? Sounds too good to be true, just checking for accuracy;) 7 grams per 2 cups sounds powerful :-)

[Aaron Sorensen]

It will boil tap water for 5 minutes.
2 cups of ice cold, no problem.
Fill it to the brim (20oz) and it barely boils tap water.
It wouldn't boil 18 ounces of ice cold water (without the lid).
This was without a lid, so maybe with a lid, it will work.
I was doing this on an overnight the other day at 10,000'

Others have posted they get 2 boils out of a 14 gram esbit.
I have my burner on the surface of a tray like this.
.

I just used a sharp rock to score around the esbit then snapped it in half.
I'm sure I can get a full boil on a full pot with a lid on it.
The windscreen/ stand doesn't have many holes in it and it's just under 1.5" high to the bottom of the pot.
I could feel a lot of wasted heat coming off the squared off pots, but the bowl seems to hold much more heat in.
It's crazy how little left over residue is left on the BGET style holders.

[John Eyles]

This question is kind of off the wall, apologies. You guys all talk about boiling a certain amount of water. But what is your overall cooking plan ?

I boil my water in an 1.3-liter Evernew Ti pot, using a cartridge stove; I could use Esbit instead, but that is beside my point. I mostly eat freeze-dried meals, but I decant them into quart- or pint-sized Ziploc freezer-grade bags before my trip. I then add the contents to the boiling water in the pot. I decant the GFs portion from the pot and then eat my portion straight out of the pot. I do the same thing for breakfast with packets of quick-cook oatmeal, Nido, and nuts and dried fruit.

From the small size of the pots I see in most of the photos here, I thinking people are mostly dumping their boiling water into the foil bag that the freeze-dried meal is packaged in. Though that allows a smaller cookpot, it seems to me that it's a net weight gain, because those foil bags are way heavier than a Ziploc, plus both people (for a couple) need a bowl (since I doubt anyone wants to eat out of the bag), plus there's probably a fair amount of residue in the foil bag after you're done (and probably wet residue at that). Of course, I've never used the dump-boiling-water-into-the-foil-bag method, so I could be out to lunch.

[Dan Yeruski]

It's all about boiling 2 cups of water using esbit in a stove.

a "stove" consists of a pot support and a fuel holder(burner)

A windscreen should always be used. It plays an important role in the efficiency of the stove. It controls oxygen to the stove.

What we do with the 2 cups of water after it boils is not our concern in the testing procedures.

Aaron has the best set-up so far. Thanks Aaron for your additional info.

[Jameson Tisch]

Aaron would you mind posting a picture of your entire cook setup?

Looks like you're getting great performance out of it.

[Dan Yeruski]

Willie Evenstop (redmonk) has got a winner also, he never has a problem getting two boils per regular tablet using the stock caldera gram cracker and cone. Eric is interested in those kinds of results for his "sweet" spot.

Willie, I for one am not interested in carrying around burned left over esbit pieces. -BG- likes the pieces, says they light easily because of the crystals sticking up from the surface.

[Jon Fong / Flat Cat Gear]

Keep in mind that the boiling point of water at 10,000 ft is 193.2 F. That 20 F delta is pretty significant. Your results are still very encouraging, keep up the great work.

[Dan Yeruski]

I did 2 tests using pieces that broke off of 4 gram tablets. I weighed the pieces and used 9 grams of fuel in each test. Used an aluminum pot, stainless steel pot support, stainless esbit tray,stainless steel windscreen, 2 cups of 65 degree water start temp. I achieved a boil in each test. Using the straight wall windscreen I might be able to get a boil with 8 grams of fuel.

[John Eyles]

>> What we do with the 2 cups of water after it boils is not our concern in the testing procedures.

You're right. Sorry. I'll start another thread.

[Dan Yeruski]

Quoting Eric Blumensaadt (Danepacker) just to bring us back on track:

As mentioned here in a few posts,

1.The DISTANCE of the ESBIT flame from the pot bottom is important for maximum efficiency.

And also
2. The SIZE of the pot (i. e. amount of wear to boil) also greatly affects boil time.

3. The SHAPE of the pot (i.e. wider than it is high) is important as the ratio I just described had been proven to be the most thermally efficient.

4. The SHAPE of the "wind screen" (i.e. Caldera cones have proven to be the most efficient)

5. Finally the "JUICE RESERVOIR" of the BEGIT tablet holder permits the liquid ESBIT residue to be retained for burning, almost doubling burn time.

So I think I may have found the "sweet spot" for these parameters.

My CC Sidewinder stove is sized for a 3 cup Open Country anodized aluminum pot/lid. Using a BGET tablet holder on the included small aluminum ground base seems to be the optimum height for the ESBIT flame. I can easily boil 3 cups of 50 F. water in 8 to 10 minutes, depending on ambient temp., using one tablet. For longer burns I use two tablets side-by-side, such as cooking spaghetti noodles or other pasta, heating reconstituted DIY dehydrated spaghetti sauce and for frying omelets and pancakes. (Yes, I do actually cook with my ESBIT stove.)

So size of stove and amount of water to be boiled are important variables with ESBIT stoves. And using some kind of ESBIT holder (BET or pop can, etc.) that contains the liquid residue for burning greatly affects tablet burn times.

BTW, see my recent post about the WalMart mini skillet that nicely fits this size stove.

[Gary Dunckel]

"Using a BGET tablet holder on the included small aluminum ground base seems to be the optimum height for the ESBIT flame."

So what IS that optimal distance, Dan? The distance from the TOP of a fresh Esbit tab to the BOTTOM of the pot. Please do tell…

(I know you hate thread drift, Dan. So if you don't tell me that distance, I will totally derail this thread by expounding upon my childhood, about being born at a very young age, and how/why I got kicked out of kindergarten, things like that).

[Bob Gross]

Gary, maybe Dan agrees, but the optimal distance is variable depending on your exact cook pot size and shape. Dan is dealing with the BGET tablet holder, so he can vary that distance.

I've generally used the standard tri-wing burner, and I place my Snow Peak titanium bowl on it and never bother to measure distance.

If you do enough testing, you will see some distance that works best for fuel efficiency, then you will see a different distance that works best for boiling speed. But each distance changes when you vary other factors like cook pot size, water volume, water temperature, uncontrolled wind, etc.

You can set up a test at home and be totally confident about one distance. Then you go test it in the field and you will see slightly different results.

–B.G.–

[James Marco]

Try it, you'll like it.
It is an upgraded BGET with heat focusing tunnel/pot holder built in.
Good to excellent efficiency.

[Dan Yeruski]

Gary, the distance is not written in stone.

My recent tests were conducted with a BGET tray with 2 four gram tablets side by side with 1/2 tablet on top. 1/8" raised up off ground.

I can say the "sweet" distance from ground zero to bottom of pot should be 1.750 inches.

We have to use that dimension because some folks will be using a full size 14 gram tablet and others will be using the 4 gram.

It was stated earlier in this thread the distance was variable and I agree with that. I'll do a search for that statement and post it as an edit to my comment.

[Eric Blumensaadt]

It would be nice if we could agree on some basic ESBIT testing standards.

Such as…

1> SIZE OF TABLET (standard ESBIT brand tab size should be a good starting place)

2> BEGET-TYPE TABLET HOLDER (I don't want to be too restrictive here to allow for innovation and comparative testing but we need to have some kind of "fuel fluid reservoir" for uniformity of testing )

3> BEGINNING WATER TEMP (includes site altitude as well)

4> TIME TO BOIL from placing pot on stove (This can allow for ESBIT flame to develop fully before placing pot on stove.)

5> DISTANCE from TOP OF TABLET TO BOTTOM OF POT (this is crucial for uniformity of test conditions)

6> MATERIAL OF POT (ti pots will take longer to heat water so aluminum is recommended FOR TESTING)

7> AMBIENT AIR TEMP (lets aim for somewhere in the 70s F.)

"Stove" (pot stand and/or windscreen setup is flexible to allow for many comparisons.

As stated previously, I'm betting on my own TD Sidewinder Caldera Cone for 3 cup aluminum pot to be among the better systems.

[Gary Dunckel]

Dan and Bob, I'm sure that you both are right (saying the same thing in different ways). I was hoping for a magic number, which would likely be different with different stove/pot configurations. We have seen that guy's chart that indicates the optimal distance be between 1.25" and 1.75" from the top of the tab to the pot bottom. In my own patio, and also field, tests, I've settled on 1.25", which gets a bit closer to 1.375" as the tab burns. That's the "sweet spot" for my pop can tab holder, whether employing a simple windscreen or a caldera "clone."

The wing stove places the tab a bit too close to the pot for my liking, as it produces a bit more of the oily residue than on pots that are a little higher above the tab. I assume this is due to some incomplete combustion. If I were to use my Titan kettle (with a greater diameter) instead of my Firelite 550 pot, it would sit maybe 1/8" higher above the tab, but the distance still wouldn't be 1.25".

'Nuff said–I think I've found my own "sweet spot" for what little Esbit I'll be burning, so I'll not drift your thread further (unless you're just dying to know why I was booted out of kindergarten…).

[Aaron Sorensen]

Jameson
Here you go.

Snow Peak Titanium Bowl with added handle.
This is total weight of everything.
.
Size comparison.
.
It's nice that because of the angle of the pot, there is no extra stakes needed to hold the pot up and in place.
Even though you can't tell, the screen/ stand has a very good angle to it.
.

[Bob Gross]

"The wing stove places the tab a bit too close to the pot for my liking, as it produces a bit more of the oily residue than on pots that are a little higher above the tab. I assume this is due to some incomplete combustion. If I were to use my Titan kettle (with a greater diameter) instead of my Firelite 550 pot, it would sit maybe 1/8" higher above the tab, but the distance still wouldn't be 1.25"."

A wing stove has three pot support arms. I used some little aluminum scraps to make some spacers that fit onto the arms. This effectively raises the cook pot up a fraction of an inch, so I can get slightly different performance this way.

–B.G.–

[Bob Gross]

Aaron, we see your photos. How much Esbit do you show there, a full tablet or a half-tablet?

–B.G.–

[Aaron Sorensen]

That's a 14 gram snapped in half.

[Gary Dunckel]

Could you post a photo of that, Bob? I'd like to see what you've done. It looks like there's yet another MYOG project to put on my list.

[Bob Gross]

I gave my last ones away, but I can describe it.

You know what a standard cardboard can of salt looks like? The pour spout is made of aluminum. When the salt is used up, I pull the aluminum off, then fold it up in a Z-shape so that it sits on the ends of the pot support arms. Depending on how much aluminum you start with and how you fold it up, you can get a quarter-inch or half-inch of spacing out of it. The only tools that I used were long-nose pliers and a small vise.

If you do it badly (like I did on the first attempt), the spacers fall off the arms and dump your pot of water. Don't ask me how I know this.

–B.G.–

[Dan Yeruski]

Aaron, got a video. How does air get under your pot and exit? How tall is your pot support? What is distance from esbit to bottom of pot?

I found this as I was searching a thread…just for reference ;)

O Ye Of Little Faith!

I've burned my share of Esbit fuel. A month ago I bought a case of ten boxes of it to give to a friend for the PCT this summer.

I normally use a titanium wing stove. In fact that is so critical to my use that I keep a new spare one in my warehouse of critical backpacking gear. If the Esbit fuel tray is sized right for the fuel cube, then there will be only a drop or two of liquid fuel burning in the tray. In other words, it burns up almost as fast as it melts. With other Esbit burners, this may or may not be the case. I generally let the cube burn up, and I adjust the amount of heating or cooking to consume that cube that is already started. There are exceptions. While I am in camp, sometimes I burn a cube halfway, then blow it out. I will relight it ten minutes later for more cooking. I don't find it difficult to relight the crystals. Or, if I have a lot of cooking to do, sometimes I will split a cube in half, then lay a half cube on top of the old crystals from the last burn. Whichever, I normally burn up the cube by the time I break camp after breakfast. In the rare occasion when I have a half-burned cube still sitting around, I stuff it back into the Esbit packaging (plastic blister and foil). Then I stick that back into the box of new Esbit cubes. The empty wing stove is folded and placed into the Esbit box as well, and there are no sharp edges or corners at all. That box goes into a plastic bag to hold in the Esbit stench, and that goes into my backpack for transport. I can't quite imagine using expensive cuben fiber anything just to haul Esbit around.

So, for me, a suitable Esbit container might be a plastic bag with my aluminum foil wind screen wrapped around it.

In a completely different situation, I carry two rounds of Esbit fuel with me in a real emergency kit. All it has are two rounds, a steel bottle cap as a fuel tray, a book of paper matches, a square of foil as a wind screen, and a folding handle titanium Sierra cup. There, I am only interested in heating one or two cups of water, and I don't worry about Esbit liquid or crystals or anything like that.

–B.G.–

[Bob Moulder]

Eric,

I would also add to your list: DEFINE BOIL

Even adjusted for altitude, I've found through testing different kinds of stoves that reaching the theoretical boiling point for a given altitude is attained (and sometimes not!) only after the water is boiling vigorously for a substantial amount of time… several seconds in the best case scenario for what anyone on Earth would describe as a "full, rolling boil". What I would define as a "by-gosh boil" consistently occurs around 200-202°F where Esbit is concerned. There are boiling bubbles steadily rising from the location where flame meets pot, but the external heat loss exceeds energy output from the fuel source such that 212°F will never be achieved.

Today I had some .005" titanium sheet, some time, a BGET template from Brian's website, some good scissors and a metal straightedge to assist folding, and made myself a BGET Esbit tray. It came out very much on spec. Easy to make by using double-sided scotch tape to stick the template directly to the Ti, and easily removed by burning off the template and tape with a Bic lighter. Well, it was easy except for the folding which was something of a bitch. Made easier by using a steel straightedge to steady things.

My test boils suggest to me there's a small but discernible improvement with the BGET and some validation of the notion that it keeps the "melted juices" in the tray. I was using an old Evernew 1.3l Ti pot with CC. Elevation was 100ft ASL, ambient temp 52°F (yes, it's June 2!).

I did 3 boils using 4 cups of tap water each time at 46°F using one 14g tab, one 14g + 7g (half tab) and one 14g + 4g (half tab shaved down).

With the 14g tab it got up to 178°F, almost the same as with other Esbit trays. With the 14+7 it attained a full boil in 14 minutes and boiled for more than 5 minutes thereafter… an undisputable full boil with the temp getting up to 210°F. With the 14+4 tabs it got up to 202°F and bubbled enough that anybody would say it was boiling.

This is right in line with Dan's observation of 9 grams for a 2-cup boil and Aaron's boil at 10,000 ft using 7g, keeping in mind Jon's observation about the significant boiling temp delta between sea level and 10,000 ft. With regards to fuel efficiency with Esbit, this has got to be very close to the maximum possible.

It also does seem to burn a little more cleanly. And the weight of 3g total for the burner and aluminum flashing base sheet is pretty darn good.

[Aaron Sorensen]

Sorry Dan, but video's of water boiling are the most boring thing in the world.
Not going to do it.
The bottom of the pot is 1.75" off the ground and the bottom of the cube is at 1/4" height.

Here is the beat up windscreen/pot holder.

.

[Author]

Posts