Alcohol Stove efficiency
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stefan hoffman
(puckem) - F

Locale: between trees
"Alcohol Stove efficiency" on 12/23/2010 15:30:42 MST Print View

This all sounds awefully familiar.

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Alcohol Stove efficiency on 12/23/2010 16:05:35 MST Print View

Franco,

>>The single main advantage to me personally is not having to deal with a toxic substance
True . In the end it is down to personal preference and not everyone is paranoid.
Franco<<

Among my stove/fuel options that I have available in my home for hiking there exists Heet, Everclear and canisters of propane/isobutane gas.

Due to my personal preference I have settled on an Optimus Crux stove and fuel gas canisters as my preferred method. Proper planning prevents poor performance and my trips are well planned and timed for mileage and fuel usage with ample cushion for unexpected events.

The fact remains that the substance that makes DNA denatured is poisonous. When I am hiking I would rather reserve my water for cooking and drinking. Having to use it to wash my hands due to a "fuel" spill so that I can continue to prepare and eat my food is a waste of resources.

Many others on this forum make the same statement about not caring to use DNA because it is in fact toxic. Paranoia is not the issue. In making your above statement you have generalized all of us who choose not to use DNA because of personal preference and careful thought into a group that you have "diagnosed" as paranoid!

Merry Christmas.

Party On,

Newton

John Roan
(JRoan) - MLife

Locale: Vegas
Alcohol Stove efficiency - what about Esbit? on 12/23/2010 18:17:08 MST Print View

Not to throw this off course, but if you're talking fuel efficiency, I think you need to consider Esbit. I've been doing a lot of testing with Esbit lately, and I'm convinced it is more efficient than alcohol. My research is incomplete, but I'll share it when ready. What I've found is that setup makes huge differences in efficiency...distance from pot, device to slow/control the burn, wind screen setup. The most fuel effecient tends to take longer to boil, but you're probably not in a big hurry once you stop for the day. Think about .25-.50 (worst case) ounce of fuel to boil 2 cups, .10 ounce stove, no fuel bottle.

Of course there are drawbacks...black residue on your pot, some don't care for the smell. Good points...it can't spill, can be mailed via USPS (ground only) for resupply boxes.

Hikin' Jim
(hikin_jim) - MLife

Locale: Los Angeles, CA, USA
Re: Alcohol Stove efficiency - what about Esbit? on 12/23/2010 19:59:11 MST Print View

> I've been doing a lot of testing with Esbit lately, and I'm convinced it is more efficient than alcohol. My research is incomplete, but I'll share it when ready.

I'll look forward to seeing your research (even though I hate the smell of Esbit).
My experience: There are so many factors that affect efficiency*, it's really difficult to make hard and fast statements about what's going to be lightest. Not to discount the value of research, but at some point I think people have to experiment with their gear in the conditions in their area.

In particular with alcohol stoves, the design of the stove makes a big difference. My White Box stove burns really hot but goes through its fuel quickly and isn't particularly efficient. My homemade open jet Pepsi can stove is more efficient (if I place the pot directly on the Pepsi can which slows things down a bit). Comparisons between alcohol and canister stoves will vary quite a bit depending on whether or not I use my White Box or my Pepsi stove as the basis for my comparison.

Again, I'm not knocking research; just trying to put things in a "real world" perspective.

Some things are for sure: having to carry a second canister is something to avoid. I'll generally switch to a bigger canister or switch to a different type of stove if I think I'm going to be packing a "dead" canister towards the end of a trip.

HJ

*pot distance from burner
windscreen used -- how good is it, how is it positioned, etc.
wind speed, direction, and consistency
air temp
water temp
pot shape
pot size
pot color
pot composition
burner type
flame height
fuel used
etc.
etc.
etc.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Esbit on 12/23/2010 20:10:28 MST Print View

Esbit - very feeble flame, takes forever to boil. Yeah, nasty smell and soot on your pot. I don't like it : (

Thruhiker says it's .25 ounce to boil 1 pint, the lightest weight stove/fuel.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Esbit on 12/24/2010 03:29:30 MST Print View

Esbit is slightly better for heat content than alky. Theooorteically it can be better. But, that soot means you do not burn all the available fuel cleanly, soo it is about the same. It packages a bit better, carries easier and requires little in the way of stoves. The gram cracker works fine. On the down side, it is smelly and coats the bottom of the pot with a sticky soot that does not wash off easily. I am *not* Mr. Clean, but adding to the normal hiking grime doesn't seem like a good idea, though, it takes a couple days to build up enough to start getting soot around.

Hell, why even use a stove? A wood fire works well...again, sooty. And in some places illegal or not available.

WG is my choice. I carry a 17oz stove, that gets between .25 and .35 oz per liter. It burns clean. I use a bit of alky to prime it to cut down on soot. An old water bottle, recycled for use as a fuel cell, easily packs. A cap with a piece of tubing epoxied in makes a great refill kit. Mostly, I never spill any. On low, it burns a couple hours on 4oz. Enough to do 12L. Not exactly ultra light, but really efficient for long 2-6 week unsupported trips.

You can burn parafin. This is also easy to pack. It makes a good stove, but burns sooty. Again, it looses efficiency.

I have tried a LOT of burnable fuels: Xylene, acetone, unleaded, alcohols, parafins, bees wax, vasalene, deisel, kerosene, motor oil...probably a few I have forgotten at the moment. 'Corse, I have been at it for better than 40 years.

I prefer two fuels: Alky and WG. You *can* blend the two to about 10%. This has the effect of burning much hotter in an alky stove (10%WG/90% alky.) But it burns sooty. Some of the additional fuel heat from the WG is wasted in soot, but I can get ~.4oz
per pint. Not worth carrying it generally. Even if it does have higher fuel heat.

Anyway, The divide for taking alky and WG (or canister) for me is between 3-5 days. It sort'a depends on if I will be doing any fishing and extra cooking...mustard greens, fried dandelions, trout & corn bread, etc... Alky is not the best for cooking on. If I am peak bagging, it always goes. If I am out canoing, never. Like everything else in the pack, it depends on what I am planing that week.

Brad Groves
(4quietwoods) - MLife

Locale: Michigan
model of stove on 12/24/2010 08:16:14 MST Print View

In most conditions I use less than a mass ounce of alcohol in my Ti Tri/Caldera. Normally a bit under 0.75 oz. Some time ago I did weight efficiency calcs & found that for my purposes, canister stoves edged out alcohol somewhere around 9 or 10 days, IIRC. The thing is, if I were doing a 14 day trip with a canister stove, I'd carry a bit less weight for the first 4 days... then I would carry progressively "more" weight (compared to alcohol) for the last 10 days of the trip. For me, an easy decision: carry less weight for more of the trip.

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: model of stove on 12/24/2010 11:09:46 MST Print View

Hi Brad,

>>doing a 14 day trip with a canister stove, I'd carry a bit less weight for the first 4 days... then I would carry progressively "more" weight (compared to alcohol) for the last 10 days of the trip.<<

Very good point. :-)

The above quote from your last post is the reason that I plan ahead and ship a resupply box to at least one point on a 2 week / 14 day hike. Recently on another thread I was investigating if it is possible and how to ship fuel canisters ahead in these resupply boxes. I also looked at buying them locally after arriving at my starting point or midway through my hike.

Merry Christmas to you and yours, ;-)

Party On,

Newton

Mark Verber
(verber) - MLife

Locale: San Francisco Bay Area
Re: Esbit on 12/24/2010 12:15:12 MST Print View

> Esbit - very feeble flame, takes forever to boil. Yeah, nasty smell and soot on your pot. I don't like it : (

depends on the stove. The 8 minutes esbits takes an a caldera cone isn't too bad. Not the 4 minutes of a canister, but it's fast enough for me.

To me, "Forever" was the 15+ minutes it took for the most efficient alcohol burner I found find / mase. It used between .2-.5 oz of alcohol to bring 16oz of water to boil depending on the conditions.

The soot form esbits is really minor with good combustion. I can easy clean the bottom of my pot with a used tea bag. Obviously, scrubbing isn't required since a tea bag isn't up to that.

Yeah.. they smell. Don't last long. I won't say I have gotten used to it, but everything else works pretty well so I ignore it.

> Thruhiker says it's .25 ounce to boil 1 pint, the lightest weight stove/fuel.

that's my experience as well if I am boiling small amounts of water because the high BTU fuels also require more sustainable containers.


There is a caviet though ... If I am doing a larger pot (>1L) I have found that canisters are better. I suspect that's because the small heat output of the esbit gets radiated away while a large amount of water is being heated.

--Mark

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Esbit on 12/24/2010 17:56:53 MST Print View

I find it is crazy to talk about the speed of an esbit boil unless you mention the start temperature, mostly of the water. I find it to be awfully slow if I start with 35 F water, but it is reasonably quick with 65 F water.

If I am on a trip and all I have is snow melt water, that tends to be pretty cold. So, I pick up the raw cold water and leave it standing in open air for a while before I try to boil it. If the open air is 65 F, that helps.

--B.G.--

Edited by --B.G.-- on 12/28/2010 16:46:43 MST.

John Roan
(JRoan) - MLife

Locale: Vegas
Re: Re: Esbit on 12/28/2010 16:14:19 MST Print View

FYI, I have found in my tests with Esbit, the distance from the flame to the container can make a HUGE difference in fuel efficiency and boil time. Not to be confused, an efficient boil could take a very long time (i.e. not using much fuel), and a fast boil generally takes more fuel. For me it's about finding the perfect balance or the sweet spot. The Caldera Keg-H is a great one to test different heights with since you can slide the "beer band" up and down to change the distance from the flame. But generally a low and wide pot will boil more efficiently than a tall narrow pot like the Heineken can.

To Bob's point, the elements play a huge role as well...temperature, elevation, humidity, etc. I guess this is why the subject intrigues me so much, because the "sweet spot" is so hard to find. That and we spend so much time talking about gear and not enough time talking about fuel and nutrition weights. Once you have your base weight pretty low, these other factors are the next logical step.

Just my two cents :~)>

Mark Verber
(verber) - MLife

Locale: San Francisco Bay Area
Re: Re: Esbit on 12/28/2010 22:14:21 MST Print View

> I find it is crazy to talk about the speed of an esbit boil

reasonable point. My timing was for the cooler end of my "normal" conditions which is air temp of around 30F and water temp of... well I am not sure... but it's snow pack fed, so certainly not 65F.

--Makr

Hikin' Jim
(hikin_jim) - MLife

Locale: Los Angeles, CA, USA
Re: Re: Re: Esbit on 12/29/2010 08:31:50 MST Print View

FYI, I have found in my tests with Esbit, the distance from the flame to the container can make a HUGE difference in fuel efficiency and boil time.

John,

In your experimenting, have you noticed a trend as to about how high your pot should be above your burning Esbit cube? I've considered using Esbit in my Caldera Cone with just putting the Esbit cube on a folded up piece of aluminum foil laid on the ground. My fear with that set up is that the Esbit would be at a less than optimal distance from the pot (too far away) although with the cone set up being what it is that may not be as big of an issue as it otherwise might be. I'm just curious if you've developed any good rules of thumb in terms of pot height.

HJ

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Esbit & Caldera Cone on 12/29/2010 09:13:09 MST Print View

From the Trail Designs web site, regarding the use of Esbit and their Gram Cracker Kit:

"The kit contains [a] solid fuel stand set to the correct height for the Caldera Cone system, 2 side panels to control the burn, ..."

Anyone with a Gram Cracker could chime in to tell you the height...

(I sold mine.)

Edited by greg23 on 12/29/2010 09:14:12 MST.

John Roan
(JRoan) - MLife

Locale: Vegas
Esbit on 12/29/2010 12:14:05 MST Print View

HJ,

I think there are too many variables to determine a rule of thumb for all Esbit stove setups. It seems that the type of wind screen limits the amount of oxygen fed to the Esbit, and whether you use a TD Gram Cracker or something similar to control the burn or not has an effect as well.

There is an article at thru-hiker that examines this subject, but it doesn't appear he used a wind screen, so in my opinion less than real world results. His tests show 1.25" being the optimum distance, but my testing with two different Caldera Cones shows more like 1.75". Again, my research is not complete yet so take that with a grain of salt (or Esbit).

I'm skeptical as to the Gram Cracker being "set to the correct height" for all Caldera cones, as the distance from the floor to the pot seems to vary model to model. This in my opinion is due to the newer models are made to nest inside the pot (i.e. Keg-H, Sidewinder). Maybe the guys from TD will chime in on this one.

John

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Esbit height on 12/29/2010 12:55:51 MST Print View

Actually, I spoke with Rand on this subject. He said there was some variance between the different pots and cones.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Re: Esbit on 12/29/2010 13:18:01 MST Print View

"I've considered using Esbit in my Caldera Cone with just putting the Esbit cube on a folded up piece of aluminum foil laid on the ground."

I'm not sure that your method will get good results. I've burned a fair share of Esbit in my time, and I really think it works better to get the cube up in the air a bit. Notice that all of the commercial Esbit burners elevate the cube to at least a half-inch, and some are higher. I have one MYOG Esbit burner with the cube one inch off the ground, and it works the best for me. It seems to allow better draft.

Factors like that (draft, windshield, height, etc.) seem to make a big difference with Esbit since it is such a low-power heat source. Some people stand the cube on end instead of down flat.

If you don't have an Esbit burner that will elevate the cube, then consider taking an ordinary wooden matchbox and covering it with aluminum foil.

--B.G.--

dale stuart
(onetwolaugh) - M

Locale: Pacific NW
esbit height on 12/29/2010 14:27:14 MST Print View

First -I did the MYOG caldera Heinie keg without the lip/wrist band support/stopper.
I made the cone from flashing with a interlocking seam that grips the keg perfectly below the top protruding ring.
2nd - I use the Esbit brand stove, three legged fold up style.

The height of the cone is such that the now hanging keg just hits the 3 legged esbit stove supports, thereby getting optimal pot height. (At least one would think it's optimal since Esbit engineered the stove).

This has worked perfectly for me and gives possibly a better heat transfer since more of the keg is in the heated cone. Yes the keg gets dirty, I normally use some moss hanging from the trees to scrub it off - but then again replacing it is not a big deal. It's under 3oz. and it all nests well inside the keg leaving room for a weeks worth of fuel. It still works with alki if one wants to bring it along for backup.
One Esbit tab boils 2 cups easily, only hitch is having to raise the cone with the keg to pour water out. (just use a bandana to grab cone/keg where they meet.

It's been well used but here are some pics.keg colage

-Dale

John Roan
(JRoan) - MLife

Locale: Vegas
Re: Re: Re: Re: Re: Esbit on 12/29/2010 14:37:56 MST Print View

"I have one MYOG Esbit burner with the cube one inch off the ground, and it works the best for me."

Bob, do you have a photo of your MYOG version?

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Re: Re: Re: Esbit on 12/29/2010 14:56:53 MST Print View

No photo, but it is simply two rectangular pieces of titanium slotted so that they fit together in a vertical X. Then there is a large notch down from the top, and the Esbit cube is placed on a piece of perforated aluminum heat sink metal that rests on the X in the notch, and is about 1" off the ground. The perforations help with the draft from the bottom.

From the top of the cube up to the pot is the "flame height" that you want to be roughly 2". Therefore, the whole thing ends up being somewhat more than 3" tall. So, this is a titanium burner plus pot stand. The thickness of the titanium pieces will dictate the overall weight. You can take it apart into flat sheets and put it away inside your wallet.

I made mine with a hack saw. Note that titanium is extremely hard stuff to saw, so you better bring your lunch.


Esbit burner


--B.G.--

Edited by --B.G.-- on 12/29/2010 15:29:12 MST.