Anybody have tips or instructions for making an esbit stove?

Also, any idea why some esbit stoves elevate the tablet?

Edited by dpark on 03/12/2011 01:56:48 MST.

An Esbit burner won't really work right unless air can be drawn up from below the level of the Esbit cube. It doesn't have to be a lot, but something like one inch really helps. You can burn an Esbit cube on the ground, but you won't get nearly as much heat into your mug. A windscreen is very important from the level of the cube to the top of the mug.

If your Esbit cube burns inefficiently, then you end up using two cubes at the same time in order to get enough heat going, and that is not good except in an emergency.

--B.G.--

Bob, what do you think is the optimal distance from the top of an Esbit tab to the bottom of the pot?

Edit--and how high should the Esbit tab be elevated off the ground?

Edited by Zia-Grill-Guy on 03/12/2011 15:08:43 MST.

The distance from the top of the Esbit cube to the bottom of the cook mug varies as the cube burns. I would have to go measure some of these that I've built over the years. As I recall, it needs to be at least 1.0 inch, but probably no more than 1.5 inch. You also want to leave some wiggle room in there in case you want to stand the cube up on end instead of down flat. Compare my numbers to what you find on commerical Esbit burners. If you make that dimension too small, then the wrong part of the Esbit flame is hitting the cook mug. That results in extra soot deposited and reduced fuel efficiency.

Elevation off the ground is also a bit flexible. Mine all leave the cube at least 0.5 inch high. I believe I built one that left the cube more than 1.5 inch high, and it didn't accomplish anything except to use up more titanium metal in the burner construction.

You must have a windscreen that will block all wind blowing in from almost any angle. However, you need to have air holes or vents or an opening around the ground level so that cold air gets sucked through there, up slightly into the burning flame, and then the hot air goes straight up from there. Also, if your windscreen is so tight that you can't get your finger between it and the cook mug, then you are probably cutting off the exit air flow, which is not good. As a general rule, I leave anywhere from 0.5 inch to 0.75 inch of exit air flow space around the cook mug. On a mild summer day, I will use only ordinary aluminum foil for a windscreen. As the weather conditions get more challenging, it is nice to have something a little more foolproof.

There is always a fool who can overcome any foolproof scheme.

--B.G.--

Your numbers seem pretty consistent with what I've seen with my ti-wing and also Esbit's bulky folding thing. What had me a bit confused was that the Esbit brand stove allows for two different heights 1.125" and 1.25"). The ti-wing looks to be .75-1.0". This makes me think that there is a range of efficient "top-of-tab-to-bottom-of-pot" distances. Guess I'll have to play around a bit. Thanks for your reply.

Edited by Zia-Grill-Guy on 03/12/2011 16:23:59 MST.

Bob
Any chance you could add some photos of your work?

Sorry, another question. What is the difference between burning the cube on it's flat side vs. narrow side up?

First of all, you know what the titanium wing stove looks like. Something like that has been around for a long time.

Second, if you want to go ultralight, then the Gram Cracker does it.



I have one of those sitting around, and then I got some titanium foil for a project, so I made some similar in shape to use up the titanium scraps.

The heavier folding Esbit stove is OK if you need that much of a pot support. Otherwise, it is too heavy for me.

Then there is one that I made out of some heavier titanium sheets.



The problem there is cutting the darn stuff. You need a Dremel tool or a good hacksaw. Titanium is very hard stuff. The finished burner looks like this. It has a sort of built-in pot stand.



Photos? No, I don't have any film in my camera right now.

--B.G.--

"What is the difference between burning the cube on it's flat side vs. narrow side up?"

I ran some tests on that once twenty years ago. It seems like it changes the burn rate, since the cube is not a perfect cube. Its rectangular shape can be laid flat, on the long side, or on the end. With some of these Esbit burners, you can stack the cubes two deep, and that will supply more heat for a larger mug of food.

However, you can't make a silk purse out of a sow's ear. Esbit is not a perfect fuel for long-term use. I think it is an excellent emergency stove, or a "one night out" stove. I used one on a five day trip for two eaters, and it was painfully slow when there was much breeze. I think I used the folding Esbit stove for that one, and it was the 0.9L Evernew titanium cook pot. The poor little Esbit cubes were overwhelmed by the task at hand. Forget about trying to melt snow unless you have dozens of Esbit cubes, which is not practical.

--B.G.--

I measured 45mm(1.75") from the bottom of the pan to the top of the stove supports on the classic folding Esbit stove. I would take this as the optimal height from the manufacturer--- they have been making the stove since WWII, so there has been plenty of time to make adjustments. The fuel tab is 14mm thick x 24mm x 32mm.

The wing stoves I have measure 33-35mm from the bottom of the fuel tab pan to the top of the pot supports. There is a 6-10mm variation on the supports-- the supports are stepped and the pot diameter will make a bit of difference on height. I assume that the wing stove makers are less precise and were looking at small cups for warming drinks and food vs. all out boiling. One stove is stamped steel, the other is titanium.

I was going to use a tuna can placed bottom up to be used with an aluminum flashing and tent stake windscreen/pot stand. From the previous comments, some ventilation is in order and it is simple enough to drill some holes around the perimeter of the fuel tab. Esbit made slots around the fuel tab area, so I assume it is important. I'll need to make some holes in the sides of the can as well. FYI, there is about 10mm clearance under the stove. My idea was to have a windscreen/pot stand that could be used with Esbit or a pop can alcohol stove. My plan for the wing stove was for use with a Ti Sierra Cup for a hot drink, dried soups, or hot water for instant oatmeal and the like.

Interesting question on setting the fuel tab on edge. I would guess that laying flat gives more surface area and a hotter flame--- possibly for a slightly shorter time. Esbit designed it flat, so I assume that is optimal.

I only carry Esbit as a backup to stove failure or possibly as a fire starter. I'm wondering just how hot it burns. I'm thinking that just carrying tinfoil to cover the top of a burner that isn't working and the bottom of a pot would get you through the trip without the clean-up mess on the top of a burner and twisted around the pot supports or bottom of a pot? Would it burn through? I'm assuming I have my usual windscreen anyway. What do you think?

Edited by Meander on 03/12/2011 18:30:45 MST.

Esbit burns at 1400 degrees F. You don't want it near a canister. You can improvise an Esbit stove with a few rocks.

for exzample

titanium model in Japan. @1mm titanium


http://hikersdepot.jp/modules/ultralightgears/index.php?page=article&storyid=223&storypage=1

Since you already need a windscreen and you may have some stakes. how about something like this:

The idea is simple and could be good but...... you do need something of a platform. When the Esbit starts to burn, it'll become smaller and eventually fall through the gap in between both stakes.

The Esbit platform can be practically any material that will support the cube, allow air to get to the cube, and not allow the melted bits of the cube to drop down. It should probably be metal.

I have successfully used one square inch of aluminum screen, and one square inch of perforated aluminum heatsink shield (scrap from a power supply). One square inch of titanium foil would work.

--B.G.--

Keep in mind I didn't actually build this thing yet but I been thinkin about it (I better get a patton! hehe). Yes a tray would be needed. I was thinking about a 1in square of stainless steel screen or someting. In fact I have a kitchen strainer that's about to go in the garbage, hmmm.

I was thinking about this because my Ti wing esbit stove is kinda wobbly with the pot on it. I started to do the stake/wind screen thing for the pot with the wing stove under it. The next logical progression was to get rid of the wing stove completely.

I bet you could use an open "tea light" style burner on it too.

OK, I took an old wind screen for my SP600 and poked some extra holes in it. I made a tray for the esbit tab.













No test burn yet. I'm down to 3 esbit tabs. I may try a tea light burn later.

Edited by magillagorilla on 03/18/2011 21:33:33 MDT.

I made more peg holes so I could adjust the burner to pot distance. Also tried to use a can bottom. I was thinking teh can bottom could double as an alcohol burner on one side and an esbit burner on the other. My test burn for alcohol didn't get me a full boil though. I tried a tea light, but honestly I have never got 2 cups to a boil with one, in any configuration.

Edited by magillagorilla on 03/19/2011 11:55:40 MDT.

Hi Daniel,

Even though you were able to adjust the burner to pot distance, you still weren't able to get 2 cups to a boil in any of the tea light configurations???

What were these distances in your different experiments? And what was, in your opinion, the distance where you got the best performance (hottest water)?

I'm burning a Esbit standing. That way, the backing plate with holes is not needed.

Daniel,
keep it simple.
make a mini-caldera cone.
it's a very stabile construction
https://picasaweb.google.com/ivovanmontfort/Zelfbouw#5340427318674597586

I got the hottest water at about 1.5in gap from the top of the tea light burner to the bottom of the pot. My spacer holes are about 3/4in apart. I also just realized that I was not using 16oz of water but more like 20oz. The water had little bubbles and was near boiling, just not a rolling boil. I have no doubt that an esbit tab would have had a rolling boil.


I have made a cone for my SP600. It works well but I don't like how bulky it is. I like the cylinder shaped screen because it uses less material and fits in my pot. Plus, I already have the Ti pegs in my pack, so I'm not really adding any base weight.

Hi Daniel.

Many thanks for this info (distances - hottest water). I‘m experimenting myself with several types of fuel and/or wicks and this is some of the info I’m trying to get hold of.

I've also made several cones (for my DIY alcohol stoves) and agree with you - they're too bulky.

Whilst experimenting I’ve been using (and still do) “recycled” cans as pot stands / wind screens, but when I finish this part of the “design-work”, I pretend to turn an 0.003” ti sheet -I bought from Steve Evans- into a stand/screen. I’ll post some pics, if/when my “system” works.

do you need holes under the esbit cube? It looks like the cube itself will close them off.

For allowing air movement, you don't need any holes directly underneath the Esbit cube. However, if there are holes in that little metal platform, it is likely to be lighter in weight.

--B.G.--

Ya, esbit burns fine on a non-airated surface. I was just trying to reduce the material. Now that I think of it, it may be a bad idea. Esbit gets kind of runny when it burns. I don't know if it will drip through the holes or not. I need to order some tabs and test it. Anyway, the beercan bottom is just as light and should work for esbit too.

I'm not a big fan of alcohol burners. I'm sort of clumbsy and tend to spill fuel. I also never seem to meter it properly. While esbit is smelly and leaves goo on my pot, it's pretty fool proof. 1 cube will get your water boiling. It won't leak and if I need to boil 5 times, I bring 5 cubes. It's a no brainer.

Still I like to keep my options open. My problem is that I have no local source for esbit but I can find alcohol everywhere.

I don't know if this will mean anything, but I found a good Esbit footplate material in a piece of old power supply heatsink shield. This is aluminum sheet punched full of holes, but I use only about one square inch of it. The holes are slightly less than 1/8" in diameter, and there are five holes per inch.

As a result, it weighs almost nothing. Plenty of air reaches the cube. The metal is not enough to be a heat sink to the hot cube. The aluminum is thick enough that it does not melt from the heat. The holes are small enough that the molten Esbit does not drip through it.

I made a similar one out of titanium foil, but it is slick and the holes have to be punched.

--B.G.--

I know this is about making your own, but I have been experimenting all weekend with what stove to take for a group cooking setup for 3 on the jmt this year.

I have a CC for a 900 ml bpl pot and with one cube it boils the heck out of 2 cups of water, I would estimate that there is half to .4 of a cube left when that water boils, and i did this in about 30 degrees with very cold water.

I am hoping to get 6 cups to boil with one cube in my new 2 qt set up I ordered this week.

i know its a stretch, but hey I can always add wood, or use two tabs, or try alcohol.

so far esbit wins out over any method I have tested to boil 2 cups (canister, alcohol or esbit)

BUMP............ :)

Yes I am thinking about going esbit, any good links with DIY? I have a sheet of Ti foil by the way.