Zelph's Fancee Feest stove burns cleanly with ethanol (I use reagent grade ethanol just because I have it.) Other stoves I tried did not burn cleanly with ethanol.

With isopropanol, soot is generated though.

Do you have a photo of this particular stove?

I don't know of any stoves that burn cleanly on high concentration isopropanol. I've heard of guys buying 70% concentrations from the drug stove and doing OK with that.

HJ
Adventures in Stoving

I have 2 stoves that will burn iso91 clean. The Super Stove with reduced pot support height and the Ring of Fire stove. Photos of these stoves have been posted on Whiteblaze.net, youtube, here on BPL and bplite.com. nobody remembers them, sniff sniff :-) I have a prototype that burns kerosene cleanly. Made that one 5 years ago, posted it on whiteblaze. Nobody is seriously interested in exotic stoves. They want what everyone else is using....alcohol or canister.

Edited by zelph on 11/17/2011 20:43:56 MST.

Zelph is taking the time to state the obvious, since it's an issue dear to his heart.

We like to differentiate stove performance based on a few finite categories; canister vs. alcohol vs. white fuel, whatever. It's not even close to that simple.

Denatured alcohol (in the U.S.) is about as vague a "definition" as exists.

We don't assume that our propane grill will run on a natural gas supply(vague), we don't try to hook it up to an acetylene tank either usually, or some combination of various gases and call it good.


Ranting as usual, but the point is, in most applications, stove burner performance is *highly* tuned based on the requirements of the fuel, and it's optimal combustion concerns given the application, and if we want optimal performance from "alcohol" we need to consider that.


However, in that vein, I'll say that it's up to the alcohol stove makers to clarify what fuels and conditions are ideal. Cannister stove makers do that, by simply limiting their products to a singular platform.





Personally, I like to design my alky stoves around 190 Everclear, since it's about as clean as it comes, and is on par with a fake cyanide tooth in making you forget (and feel like sh$t in the morning). I tried sunnyside based on the paper, a couple years ago, and wasn't impressed.

"I have 2 stoves that will burn iso91 clean. The Super Stove with reduced pot support height and the Ring of Fire stove. Photos of these stoves have been posted on Whiteblaze.net, youtube, here on BPL and bplite.com. nobody remembers them, sniff sniff :-) I have a prototype that burns kerosene cleanly. Made that one 5 years ago, posted it on whiteblaze. Nobody is seriously interested in exotic stoves. They want what everyone else is using....alcohol or canister."

You have a prototype that burns kero cleanly? Wow...that stuff really requires some fancy foot work. If the photo's still exist, post a link or post a new set here. I just LOVE burnin' stuff...hey, hey... Long as it burns cleanly, the wife may have something to say about the smell...

BTW: White gas and ISO mix fairly well at a 10%ISO/90%WG ratio. It burns clean in a WG stove.

I think Javen is right on the money. Zelph thx for sharing your stoves, I'm new to them and I'm kind of overwhelmed at what I saw on your site.

If I'm not mistaken, a stove is an engine, converting one form of matter into energy. As such each engine design may perform differently with differing fuels. My Evernew definitely isn't designed to use high ethanol content fuels without sooting. In my mind I feel that detuning a fuel to make it work in a stove isn't the best choice unless it's your only one. It would be better to use a stove designed for a higher energy fuel then go from there.

Another thing I noticed from using Green DA is the stronger scent from combustion. It wasn't that noticeable when I used it once but for testing, I ran back to back to back tests and the collective smell was significantly stronger than what I'm used to with SLX. Perhaps it has something to do with the higher MIBK content than SLX? (Methanol via HEET is not an issue since it doesn't seem to produce much at all).

I went out and did a little testing of my own with various stoves this past weekend.

My results were very similar to James'. On SLX Denatured:

Everything had nice blue flames except the two brass Trangia burners, but Trangia puts something in the burner to make the flames that particular orangish color for safety, so that's not a fuel or burn efficiency related issue.


The same stoves on "Green" Denatured:


A lot of yellow flames although the Trangias seem less affected, and the "Tall Boy" stove (back row, center) didn't have any yellow in the flame.

Green denatured definitely burns hotter and tends to make yellow flames. Stoves that are more efficient to begin with and burn with a lower flame handle the "green" alcohol better.

HJ
Adventures in Stoving

What a great test! You have a nice selections of stoves there Jim.

I'm in the process of uploading my comparison between SLX and Green DA to youtube, hopefully it comes out nicely.

I actually started out with a wider variety of stoves. The stoves in the above photo were just stoves that made the first cut.

My starting line up:


I'm basically looking for efficiency and reliability. I want to consistently be able to boil 2 cups of water in a variety of conditions (calm, windy, cold, etc.) on a minimum amount of fuel.

To weed out inefficient stoves, I conducted burn duration tests. Any stove that burns through a given quantity of fuel quickly is not an efficient stove.

"Closed" jet type stoves (back row in the above photo, the two to the right) quickly fell by the way side. Closed jet type stoves require priming which requires that some of the fuel be used for the priming which winds up shooting any overall efficiency to heck. A closed jet type stove undergoing duration testing:


Priming pan in use with a closed jet stove. Note blue flames coming out of priming pan.


"Fast" stoves (ones that boil water quickly) were eliminated next. Fast typically equals inefficient. This stove is inefficient!


I then benchmarked the remaining burners against Trangia burners. If a test burner cannot outlast a Trangia burner in a duration test, then there is little chance that the burner is efficient.


I noticed the tendency of hotter stoves to burn with yellow flames when using "green" denatured alcohol. Notice in the photo above that the only test stove NOT burning with a yellow flame is the tall stove in the middle of the back row. The tall stove was also the only stove that came close to the Trangia in duration testing.

After conducting duration tests, I did boil tests.

Side burners typically were eliminated during boil tests. Side burners generally have the problem of flame spillage where flames spill up around the pot and heat is wasted. Wasted heat = inefficient.




All of the above "weed out" procedures left me with a few open top jet stoves.


The tall stove shown above did exceptionally well in both duration and boil tests. Inside a windscreen, a notably different environment than out in the open as in my duration tests, the tall stove brought water to a boil slower than my Trangia burners (generally a sign of efficiency) and held the boil for multiple minutes. Inside a windscreen, I was getting nearly 15 minute burn durations on 3/4 fl. oz. of denatured alcohol with boils occurring around 11 minutes and lasting until nearly 15 minutes. That's pretty good.

Now, I need to "deconstruct" the tall stove that did so well. I wish I could claim the Tall Boy Top Jet (the name of the stove) as my own design, but this one comes from a stove designer here in the Los Angeles area who gave me a copy of his latest creation for testing. It did better than anything else I have including the commercially produced Trangia burners.

HJ
Adventures in Stoving

Edited by hikin_jim on 11/22/2011 10:18:08 MST.

With respect to your first screen test, you may find that the interaction with the pot will skew your results. The pot will act as a barrier limiting the amount of airflow to feed the flames. Along with that, it can take some time to optimize the stove to pot distance. Finally, the windscreen design can have a significant impact on the stove perfromance. So example, some double wall stoves work great in the open but fail with a windscreen. Inside a windscreen, the ambient temperatures can go up as high as 50F-70F. Best regards - Jon

With respect to your first screen test, you may find that the interaction with the pot will skew your results. The pot will act as a barrier limiting the amount of airflow to feed the flames. Along with that, it can take some time to optimize the stove to pot distance. Finally, the windscreen design can have a significant impact on the stove perfromance. So example, some double wall stoves work great in the open but fail with a windscreen. Inside a windscreen, the ambient temperatures can go up as high as 50F-70F. Best regards - Jon

I used to think that alcohol stoves were like universal camping tools but now I'm starting to realize that it's more of a specialty tool where you want to fit the stove-to-cookware combo to your cooking needs.

For example, while I haven't tested it "out in the field", stoves that burn a lot of fuel quickly, assuming they burn relatively clean, seem ideal for those who want shorter times to heat something up or more specifically, boil water. One that tends to burn fuel at a much slower rate would also suggest less heat energy is being produced so fuel efficiency comes at a cost of increased heating times. What used to take 3.5 minutes to bring to a boil may take 7 minutes.

Efficiency, in my feeble mind means doing more with less. A stove that uses fuel slower doesn't seem to fit that theory necessarily. While a stove's heat output could be better used if superior heating materials were used in the cookware (for example copper for titanium), since copper retains heat better, it would require less effort to maintain that heat than it would titanium. Also, since Ti resists heating more than copper would, it would require more heat energy to overcome that resistance in order to have it transfer to whatever's in your cookware (water for instance).

Everything seems to have a "this for that" tradeoff.

- A stove that burns fuel fast would suggest higher heat output so you can boil water in less time. The tradeoff is more fuel for shorter times. The caveat to this is you don't want to use it in a situation where gradual heating is involved. (i.e. cooking a full turkey at 900F in half the time is not better than cooking it slower at 450F)

- A stove that burns fuel slower would suggest lower heat output so you can keep something heated longer. The tradeoff is longer burn times at the cost of additional time to boil water. This may be the better solution for those who intend to really "cook" rather than simply boil water.

- Copper is the best heat conductor between aluminum and titanium, but at the same thickness it's also the least durable. To make it as strong as Ti, it needs to be thicker thus adding to its weight. Aluminum seems to be a decent "medium" since it's tougher than copper at the same given thickness but still a better heat conductor than titanium. The issue with aluminum is regarding health concerns regarding its reaction with your food. Even damaged anodized aluminum (which isn't easy to do) might allow exposed aluminum to come into contact with your food.

I wouldn't worry too much about the aluminum cookware for backcountry use unless you are cooking with lemon juice or something else highly acidic in an uncoated pan. You'll get an order of magnitude higher dose from taking an antacid tablet or buffered asprin...and most of the cookware used in restaurants is plain aluminum.

zelph wrote: > I have 2 stoves that will burn iso91 clean. The Super Stove with reduced pot support height and the Ring of Fire stove. Photos of these stoves have been posted on Whiteblaze.net, youtube, here on BPL and bplite.com. nobody remembers them, sniff sniff :-) I have a prototype that burns kerosene cleanly. Made that one 5 years ago, posted it on whiteblaze. Nobody is seriously interested in exotic stoves. They want what everyone else is using....alcohol or canister.

James Nomura wrote: > I used to think that alcohol stoves were like universal camping tools but now I'm starting to realize that it's more of a specialty tool where you want to fit the stove-to-cookware combo to your cooking needs.

James Nomura wrote: > Efficiency, in my feeble mind means doing more with less. [emphasis added]

James Nomura wrote: > Everything seems to have a "this for that" tradeoff.

Thx for the kind remarks and nice tips Jim!

Here are the links to my video test, please bear with me as I was super tired when I made those vids.

Green Denatured Alcohol Test: http://www.youtube.com/watch?v=jF5w5GAcJL4

SLX Denatured Alcohol Test: http://www.youtube.com/watch?v=vf8z_p6nb-Q

Hi, James,

Not bad vids at all.

Assuming that your videoed tests are representative, it looks like we can conclude at least two things from the videos:
A. Green Klean Strip denatured alcohol brings water to a boil faster.
B. Regular SLX Klean Strip denatured alcohol burns more cleanly (of course there are some stoves that will burn Green DA cleanly).

If you do more tests, I'd be curious to know:
1. How long does, say, 15ml of Green denatured alcohol burn for vs. the same amount of SLX denatured?
2. What is the minimum amount of Green DA required to boil 1 cup of water vs. the minimum amount of SLX DA required?

The really important question is (to my mind) #2: what are the minimum amounts required, respectively, to bring 1 cup to a boil? If I can carry less fuel to do the same amount of work, then perhaps it's worth it to get the Green DA. Otherwise, just stick with cheaper, generally cleaner burning SLX.

HJ
Adventures in Stoving

Edited by hikin_jim on 11/23/2011 21:04:41 MST.

Jim, good comments!


My conclusions for my specific test setup:

1. Green DA burns hotter due to higher ethanol content

2. The amount of heat generated is amplified by how the stove burns fuel mixture.

3. My stove setup won't likely burn high-ethanol content fuels clean without some kind of modification.

4. SLX and Methanol fuels (yellow HEET) are more forgiving to use in a cleaner manner.

5. Methanol is the least "stink" fuel to burn, Green DA is by far the "stinkiest".

6. Resorting to using water to tone down high ethanol fuels makes no sense when SLX or methanol fuels are readily available.

=====

Now regarding your questions, I believe I'd need to come up with a rig that can showcase those questions.

1. Obviously #1 is an issue about "time". Since the question is simple it's just a matter of measuring out the exact amounts for each DA and measure burn times. Honestly, I don't believe Green DA and SLX will vary much at all in terms of total burn times using 15ml each using the same, non-adjustable stove.

However if you're looking to use whatever information from that test to go after a more efficient burn, I'm thinking that since GDA has a higher energy content, a stove could be designed to tone down the combustion so that you can stretch the burn times versus SLX. I've seen a few stoves on youtube that are adjustable and I think those may make a better candiate to test for this.


2. #2's goal differs in that it doesn't emphasize time so much as long as you achieve a boil. This one's going to be a tougher for me. You'd have to minimize heat energy from being wasted from heating too much surrounding air around the flame source so most of it can be transferred to the pot, which should be made of the best heat conducting materials designed to absorb as much of the heat energy and incorporate something on the inside to allow it to give up heat as fast as possible.

I used to use a CPU heatsink on my old Pentium 2 made by a company called Alpha, what made it unique was it used both copper and aluminum to rid the CPU of heat very efficiently. The "hot" side was copper which likes to heat up quickly and retain heat. However a heatsink needs to get rid of it as fast as possible and copper does not do that well. Aluminum is almost the opposite, it resists heating up more than copper however it gives up its heat faster. So a pot with a solid copper bottom mated to an aluminum topside is what I'm thinking would best achieve the goals of this particular test.

NOTE: I recall reading something where Tinny from Minibulldesign hacked a Jetboil pot...

For the stove, I would forego the idea of using any stove design that requires priming as priming itself is an inefficiency.

6. Resorting to using water to tone down high ethanol fuels makes no sense when SLX or methanol fuels are readily available.

priming itself is an inefficiency.

Edited by hikin_jim on 11/24/2011 00:48:44 MST.

I believe in being able to use more efficient methods of generating heat for food/water however fuel dilution is directly impacting the efficiency of that fuel. For example in my specific test setup, using 30% less fuel would also come at the expense using additional water just to run the stove.

With cars, if you used a fuel that created a condition where your engine ran way too hot, the correct solution isn't to dilute the fuel, the engine needs to be retuned and/or altered to accomodate that fuel. Dilution IMO should be left as the last resort to make something work.

In order to use a higher energy alcohol fuel, it's my belief that it's better to use a stove that can make better use of it without dilution. I don't know how to figure this all out mathematically but since we know GDA burns much hotter than SLX for example, in order to achieve the same kind of results from using SLX, you need to reduce the flame from using GDA (burn less fuel but produce the same total heat as SLX) in order to conserve fuel.

I understand the concern for #2 however I'm sure you'd agree that for that test, the combination of fuel being used, stove design and pot material will collectively affect the results. If I chose to use Titanium pots, I'd likely have significantly different results from a person performing the same test using copper pots. Naturally certain stoves are better designed for gradual, steadier flame output than my Evernew stove so that's why I believe we would need to look at all areas and not just the stove or fuel.

I don't know how to say this other than through the use of the term "total balance". In Japan that basically means "everything has to be right and each part needs to be tuned properly to work best with each other, nothing can be out of place".

As soon as I find a decent portable copper tea/water kettle, I'd like to find out just how much boiling times vary between using titanium vs copper using the same amount of fuel. Then repeat that test to see how much fuel is needed to bring each pot to a boil simply due to the difference in materials.

I know there's quite a few people on this forum that probably did all of this many times before, I'm interested to hear what they have to share.