Esbit burner testing

Dan,

“Heat capture” that you referred to above is what the Caldera Cone type stoves do pretty much better than any other style of stove, at least to my knowledge.

The pot/mug sits down inside the cone and its bottom sits (hopefully) at the ideal height from the ESBIT flame. Heat coming around the pot/mug bottom goes up the sides of the pot before escaping out the cone’s top vents. This “side-pot heating” is the beauty of a cone type stove, making it highly efficient.

Winnowing through all the comments in this forum, particularly this thread and some of my own experience I’ll kinda re-state my “SWEET SPOT” list of ideal ESBIT stove conditions – with additions.

(** items added after reading newer comments.)

IDEAL ESBIT STOVE CONDITIONS:

1. POT SIZE-> Pot W/lid not larger than 3 cups?
2. POT SHAPE-> Wider than it is tall has been shown to be most efficient shape.
3. POT BOTTOM DISTANCE FROM ESBIT FLAME->  What is the “optimal” distance?
4. ESBIT TAB HOLDER WITH FLUID COLLECTION TRAY-> Tray gives maximum burn time.
5. **TABLET HOLDER WITH LEGS-> (ex. Gram Cracker type BEGET tablet holder) to prevent heat conduction downward to a base below the tablet holder.
6. CONE STYLE POT SUPPORT/WINDSCREEN-> Most heat conserving pot support when pot sits down inside the cone?
7. ** TABLET SIZE-> This has been mentioned. For testing purposes at least I feel we should use “full size” ESBIT tablets and half tablets since this is the most common size in use. (And testing only with ESBIT brand tablets also standardizes energy output per tablet when compared to, say Coughlan or old BPL Store tablets, some of which I still have.)

Have I missed anything?

Yes Eric.

Burner wants to be integrated with pot, so packs away well.

I have in mind the ancient Meta-71 stove/ small pot that I have, just large enough to boil 2 eggs, make a brew. The stove packs away inside the pot. But it wants to be in titanium, and a few details changed.

Also, the pot/stove system wants to be able to be hung, as an option (I’ll forgo the drawn and quartered).

Cone wants to be usable as a wood stove as well.

6. CONE STYLE POT SUPPORT/WINDSCREEN-> Most heat conserving pot support when pot sits down inside the cone?

Not necessarily.   ;^)

I have for some time thought that there is the factor of “flame dwell time” that comes into play.

Or maybe it’s not so much time as it is retention and dispersal of the hot gases on the bottom of the pot. Whatever you want to call it, it did seem to provide noticeably more efficiency with a straight sided windscreen when tested against a CC. Both Dan and I had similar experiences with repeated tests, so it wasn’t a fluke.

Dan’s latest stove design incorporates this concept and I suspect it will be quite efficient once the intake and exhaust equation is balanced.

Also, burner tray wants to be easy to clean.

These various factors are design criteria.

mama has things for me to do so a quick post of something from the past to show how we’ve advanced in our thinking…be back later:

It starts out alcohol and then turns to esbit

https://backpackinglight.com/forums/topic/40662/#comments

Dan,

If you have been able to design a stove that’s demonstrably more efficient than a cone stove I’ll be one of the he first to build one. Thank you for staying on this ESBIT efficiency path. Now if we could just find a fuel that’s hotter than ESBIT…

I guess  if you can make this new ESBIT stove my Sidewinder ti cone stove will be relegated to a gassifier type wood burner. And that’s OK B/C I still feel it’s more efficient than the Bush Buddy. (Yes, the ti cone wood burners with Inferno inert are a tiny bit more “fussy” to set up but at least you can stoke them with thumb thickness wood and leave it for 5 minutes, something not possible with a Bush Buddy.)

Eric, I have built one that is more efficient. On the previous page of this thread there is a photo of a straight wall esbit/stove with kmart grease pot that I put together in Dec. of last year while I was down south for the winter. In my rush to get back north this spring I left it in my camper. I have to duplicate it in Ti and use the newest esbit stove that I designed under the pot. here is a copy of the set-up

Now if we could just find a fuel that’s hotter than ESBIT…

Eric, I’m developing some thermite and magnesium cubes that might surpass the esbit :-)

Bob, here is a photo of the windscreen surrounding the grease pot that I did tests with and reported in the previous page in this thread. I quote the results of the tests:

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.

Well, if you roll the top of the windscreen over the pot, you could probably boil 4 cups with 1 esbit.

Jon, I think you’re right. I’ll have to give it a try. Nothing ventured, nothing gained :-)

@rmeurant, I like your ancient stove/pot system. I’ll do a search on google and see what comes up.

Thermite exothermic reaction, cool! (So that’s why the biker bar I threw a thermite grenade into burned down so fast.;o) Where the he!! did you find that “Mr. Wizard” film?

Actually I was thinking more along the lines of “detuned” solid rocket fuel. It would have to be contained so the flame could be diffused and directed, natch. A thick Ti fuel container would likely be OK. Maybe with ceramic lining?

OK, I’ll try your straight wall setup with some aluminum roofing valley sheet I have on hand.  This is getting very interesting.

@jonfong, The Caldera Cone with its tight cone-to-pot rim fit kinda does the same thing as a rolled over windscreen. No?

Dan -Yes, and when packed, it fits in the hand rather well. The lid “handle” (knob) is rather ineffective, but could easily enough take a loop.

see https://classiccampstoves.com/threads/meta-71.11679/

and also good photos of logo etc. at http://www.bushcraftuk.com/forum/showthread.php?t=41559&page=2  , who gives the total weight of the Meta-71 cooker at about 3 1/2oz. What I would describe as a muck metal (?).

Also, I am not necessarily suggesting the ideal stove or cone should fit into its pot as this Met-71 does; but the relation between stove/cone and pot needs to be integral to the design, both in use, and perhaps also in packing. “Perhaps”, because at present I use a Ti EmberLit, which of course folds into a separate flat pouch; I like it it a lot, but it is a nuisance to assemble when you are hypothermic. A further design constraint of the ideal Esbit system might include compatibility for packing a folded-up Swedish Foldacup (good enough fit here):

By the way Dan, this is my favorite pot, dimensions 3 3/4″ outside diameter, 4 1/16″ dia rim, 3 3/8″ height w/o lid, 4 1/8″ height with lid and knob. Some kind of thicker aluminum, I think. It is an Evernew pot, the only one I have ever seen, bought in Japan, but made in Korea. I include it, as it has well balanced proportions, also it is very sturdy. The only improvement I would make is to give it a bale handle; and maybe a ceramic finish would be nice. Similar proportions to the 500ml Evernew Ti (but no spout, no volume markings, no base inset for Evernew burner). It continues to give me pleasure, just “feels right”.

@rmeurant.

, from your link 2 quotes about the fuel used in your meta-71:

Nice setup Steve, they were designed to burn small ‘Meta’ fuel tablets, the type often used to pre-heat paraffin Primus stoves. These were much smaller than hexi blocks. These were popular with climbers and hill walkers back in the 60’s and 70’s, they work well. I’ve got one somewhere, and a box of the Meta fuel, all I have to do is find it now

Meta is metaldehyde http://en.wikipedia.org/wiki/Metaldehyde. The blocks were like a pleasant smelling glucose tablet – much nicer stuff than hexi=hexamine=hexamethylenetet ramine. I don’t know whether you can get it easily now.

Robert, I like what is said about the fuel ” pleasant smelling” . What is the current fuel of choice in your neck-o-the woods/location? Are they still manufacturing fuel tabs similar to the “metaldehyde?

The fuel tray for your stove is nice, has the ability to retain melted blocks of fuel. Have you used the 4 gram esbit tablets/blocks with the stove?

Dan,

I’ve used the small Esbit tabs, I think 4 gm, which I mainly use in any of my Esbit stoves, not the big ones. I actually find the 4 gm tabs the more convenient. Haven’t tried to get the Meta fuel, or ever seen it on sale, at least in the last few years. Esbit is available in some mountain shops in Korea, sometimes a little hard to find,  and some in Japan, more in the main centers. I have been advised that cleaning alcohol is more reliable for touring Japan, as any pharmacy will have it, as is the case in Korea.

I have been advised that cleaning alcohol is more reliable for touring Japan, as any pharmacy will have it, as is the case in Korea.

That’s good to know…thank you. I tried to find the availability of esbit Internationally but had no luck just these charts:

Fuel tables by country
https://thesummitregister.com/wp-content/uploads/2013/03/Fuel-Tables-by-Country.pdf

I had good luck with my test of exposing esbit cubes over a 24 hour period. I opened 3 cubes as seen in the photo and let them sit on a table out in the garage for 24 hours and then sealed them over with 2 inch wide, clear packaging tape. I then let them sit for another 24 hours and then opened them and was pleasantly surprised to find most of the odor had dissipated.  I may be influenced to use esbit more often than wood especially in times of wet weather….not gonna to happen  heh heh….Eric thinks his Cone stove is better than  Bushbuddy  Bushbuddy and other stoves can boil 2 cups with 2 ounces of fuel, been there, done that.

Dan, seeing as you’ve carefully opened those tabs up, what is the weight of the empty packaging?

@oysters, an empty pack of 3 weighs so little nothing comes up on my electronic postal scale.

I am well pleased on the absence of odor due to the venting procedure I went through. One less obstacle and now on to the next. “difficulty in lighting esbit” we have heard it time and time again that it is difficult to light. Tomorrow I’ll tell you what I have found to make it a lot easier.

The best way to light esbit is with a jet torch butane lighter that’s refillable. I found one locally and it’s the best I ever had. Holds at least 2x the amount of fuel as the mini bic…2 times heavier but that’s ok with me. The body of the lighter is translucent, allows you to see how much fuel is left.

No need to add an excelerant to the esbit to get it started. 

I prefer to focus lightning – SHAZAAM!!!

Haha!

Anyone tried say an eye drop bottle filled with alcohol? One or two drops on the tab ought to do a good job of it.

Robert, Wonder Woman does that with her bracelets, she is sooooo cool/hot

Adam, I went into my laboritory and tried the 2 drop method and it failed. 5-6 drops work well. I did 4 test and boiled lots of water, plus it stunk up my garage all in the quest for esbit knowledge 

Eric wrote:

IDEAL ESBIT STOVE CONDITIONS:

1. POT SIZE-> Pot W/lid not larger than 3 cups?
2. POT SHAPE-> Wider than it is tall has been shown to be most efficient shape.
3. POT BOTTOM DISTANCE FROM ESBIT FLAME->  What is the “optimal” distance?
4. ESBIT TAB HOLDER WITH FLUID COLLECTION TRAY-> Tray gives maximum burn time.
5. **TABLET HOLDER WITH LEGS-> (ex. Gram Cracker type BEGET tablet holder) to prevent heat conduction downward to a base below the tablet holder.
6. CONE STYLE POT SUPPORT/WINDSCREEN-> Most heat conserving pot support when pot sits down inside the cone?
7. ** TABLET SIZE-> This has been mentioned. For testing purposes at least I feel we should use “full size” ESBIT tablets and half tablets since this is the most common size in use. (And testing only with ESBIT brand tablets also standardizes energy output per tablet when compared to, say Coughlan or old BPL Store tablets, some of which I still have.)

Have I missed anything?

And so now we covered “ignition” We have heard many times that esbit is hard to light.  Now that I have experimented with the butane jet torch, I can feel safe to say the jet torch is a sure way to ignite esbit so lets add a number 8, to the list.

8. Positive method of lighting the Esbit.