Caldera Cone Under Glass

Here’s what the set-up looks like:

Thanks Dan. I just ordered both your modified and regular Starlyte with lid to try with my Caldera Cone
Sidewinder Ti-Tri Sidewinder for the .9L Evernew. One question though. Do I simply use the Starlyte in place of the 12-10 inside the cone? Do I need to jack up either the stove or the pot?

BTW, I have used your Super Stove inside this cone, and it works great. Everything fits together well, and it's very thrifty with alcohol.

If you video with no lights at dusk you will get far superior exposure of the flame patterns, even though the resolution will be fuzzy you can see very clearly what the flames do.

I found this to be the case recently when taking pictures of a new stove burn pattern, the flames were extremely easy to see.

You can experiment using indirect light sources when it is dark out too, that will create a yellowish light around the flame.

Very good idea on filming under glass upwards by the way, that's the only real way to see the behavior with pot inserted and screen closed.

Here's two examples that show how well the flame pattern can be observed with either a regular light on in the room at night or with no light. (pot stand was crooked, whoops, in case you're wondering)

John, jack up the StarLyte 3/4″. The second video in this post is the StarLyte under the cone. The first part of the video is the starlyte jacked up 3/4″ and the latter part is flat on the glass.

Thank you Harold for the tip. Your photos are a good example. We learn as we go. The more we burn, the more we learn as Jon would say :-)

John,

I have basically the same set-up as you, but I also have the "inferno" wood burning bits for the Sidewinder.

If you've got the inferno pieces as well, the honeycomb mesh that is meant to support your wood kindling is just about the perfect height for propping up the Starlyte. Dual function!

Cheers,

Chris

I have the same setup, and I have "Jacked up" the starlyte stove about one-half an inch for the best results. It puts the stove about 1" from the bottom of the pot. And BTW – I seem to get a faster boil with slightly better efficiency using the starlyte instead of the 12-10.

David, that mirrors my experience with the Starlyte. Nearly 10% more efficient with the standard Starlyte + 1/2" shim. The modified Starlyte used 14% less fuel (than the 12-10) but had a slower boil time. I haven't tested with a 3/4" shim.
Incidentally, the Starlytes were even more energy efficient in Zelph's Titan-3 windscreen (not currently on the website), but had longer boil times than in the Caldera Cone.

This inspired me to do some test boils with a 3/4 inch shim. Two boils with a standard Starlyte with 3/4inch shim compared to two boils with a 1/2 inch shim. 400 ml of water were heated from 16 degrees C to 98 degrees C. Ambient temperature was 19 degrees.
Both boils with 3/4 inch shim were faster, averaging more than 4% less time (7 minutes 28 seconds average). They also used an average of nearly 5% less fuel (11.4 grams average).
I also did a comparison boil with the modified Starlyte (only one boil with each shim). The 3/4" shim burned slightly over 5% less fuel, and reduced the boil time by more than 12.5%. The fuel use was less than the standard Starlyte (10.57g) but the boil time was rather longer (9 minutes 19 seconds.)
I did one further test, putting a sheet of aluminium foil under the modified Starlyte to reflect heat back. This reduced the boil time significantly (to 8 minutes 30 seconds) but had little effect on fuel use (10.64g).
All in all, the Starlytes are looking like a very good option in the Keg-F cone.

Thanks Dan, I will try it with them both jacked up 3/4 inch as you suggested and see what happens. There may be something that I would normally carry on a backpacking trip that could serve as a 3/4 inch shim and could also stand the heat of the stove.

David, your suggestion of having the top of the stove 1 inch from the bottom of the pot seems reasonable because the Starlytes are essentially wick stoves and this is the same height that Tinny and Smokeeater suggest for their carbon felt stoves, which are wick type stoves. I have a feeling that Dan's suggestion may give that 1 inch clearance also because he is an expert as well.

Christopher, I didn't order the Inferno gadgets with my Caldera Cone because I wasn't anticipating using wood as a fuel, but thanks for the suggestion.

I suppose I could even use one stove as a shim for the other stove. In any case it will be interesting experimenting with the two Starlyte stoves in the Caldera Cone and comparing their performance to that of the 12-10 stove. The real test will be when I take the set-up into the field at Point Reyes National Seashore along the California coast where 20-30 mph winds are common.

I know Roger, we shouldn't even be going out the door with alcohol stoves, but if it's any consolation, I like canister stoves too!. Slainte (that's irish for cheers)

Isn't the Starlyte stove the one mentioned in another thread as a stove one can use with the Sidewinder to eliminate the tent stakes? I would dearly love to have the pot sit down inside the cone as it did with my standard Caldera Cone set-up, I find the stakes fiddly and a pain to pack properly. So, do you need to raise the stove, or can you just drop the pot?

John and Diane, I have the Sidewinder with Evernew wide 0.6 litre pan. I did a few tests with it and found that it not only needs dropping down but also jacking up at the same time. I only tested it jacked up by 1/2 inch, so you probably need to try a few different heights to find the optimum for your particular Sidewinder.
The bottom cut off a drinks can works great as a shim and weighs less than 5 grams. The smallest Red Bull and Nescafe cans are the exact same diameter as the stove (at least, with the cans here in Turkey). You can also get slightly larger diameter Red Bull cans that the stove will nest in conveniently for packing.
HTH
Edited to add: When jacked up in the Sidewinder, the Starlytes (both types) were way more fuel stingy than the 12-10 stove but also slower. PM me with an email address if you want me to send you a spreadsheet with the data.

William, your listing your fuel consumption by weight made me at first scratch my head, then have a slight eureka moment, then I searched it and found this fine article on the ion stove and fuel consumption. That article covers the joules contained in fuels, the btu’s required to boil water (9 ml alcohol at 100% efficiency for 500 ml, didn’t mention which type of alcohol though, it matters, but we can easily calculate that using the data provided).

So this reminds me, virtually all online comparisons between gas and alcohol weights over trips are wrong, not all, but most. I weighed my slx fuel and found it weighs 7.6 grams per 10 ml, ie, it has a specific gravity of 0.76. That means 10 oz in a container, by volume, does not weigh 10oz, it weighs 7.6.

For example, in my current models, I get consistent rolling boils at 17.5 ml, which is about 50% efficiency give or take, which is not bad, not as good at the ion’s 75%, but not bad. At .76 sg, that’s 13.3 grams of fuel, which suddenly is quite different from .6 oz to .75oz fluid volume, or 0.46 oz per boil of 500 ml (I find it’s useful when testing to boil the standard amount so that consumption/effiency can be properly compared, too many things change when the volume of water changes, in often unpredictable ways). So all this time I’d been banging my head against the 1/2 oz boil and it turns out I’ve been past it for quite a while in my testing, due to the specific gravity/fluid volume issue of alcohol.

Another thing that struck me as I reconsidered the fuel weight vs volume, and this is yet another big plus for alcohol stoves, as if they needed more, being ultralight (both the stove and the fuel container), simple, silent, and easy to obtain fuel for anywhere, is that all along I’ve been just thinking of the volume = the mass, ie, a 10oz bottle of fuel weighs 11 oz, give or take.

then it struck me, gas is never really compared in this way as apples to apples, ie, what is the efficiency of gas in different stoves/setups vs alcohol in different setups, ie, the test has to be at standard temps, 500 ml, then by weight, not volume, of fuel consumption. That article noted that gas stoves were about 30% efficient, but it’s an old article, so that may have changed, but I certainly do not recall such matters being frequently discussed here or anywhere else when comparing the fuel stove methods.

It’s also worth noting that if you are using one of the super efficient stoves like the ion, which is giving you 75% efficiency, and if the gas stove is for example giving you 30%, then you are roughly equal in terms of btus delivered to the water.

thanks for the mental nudge William, I wouldn’t have stopped to consider this until you very correctly listed your fuel by weight, not volume.

So for totally accurate comparisons, you need the following data:

• ambient temperature, which will change the specific gravity
• Temperature of water
• altitude
• weight of 10 ml of the fuel you are using, in grams, at that ambient temp.
• weight of fuels consumed to bring to a rolling boil 500 ml of water, which I assume is pretty much 212 degrees F at or around sea level, though a thermometer will show it more accurately. this will in turn give the efficiency of the fuel/stove.
• type of wind/heat screen used, if any
• weight of fuel container
• weight of stove
• weight of screen/pot stand, if any
• Use of a real lid, ie, one that is capable of holding in some pressure. This one is almost always ignored, why, I’m not sure, it matters. A lid that can actually hold in some pressure is going to make a difference.

Once you have all these listed explicitly, you can start to make apple to apple comparisons which are actually analytically useful.

For example, here in these forums you will read all the time some post about x gas stove that weighs x or y grams, but not a word about its actual efficiency, which often could totally nullify any weight savings.

Standardized quantity of water, 500ml seems like a good one because it’s basically two cups, but not quite, it’s a bit more, which means also, sticking to one system, metric is sensible in this context since it’s easier to deal with the units.

Then we can actually see what the various options actually compare to, not that anything can beat alcohol due to the factors I listed, but the comparison is more fair then, since almost all gas stove data is always weight of fuel consumed, whereas almost all alcohol stuff online is volume, and totally fails to differentiate between types of stoves or efficiency of stoves, from what I can see, which makes a pretty major difference. It’s almost like there’s all too frequently a pre-established selection bias in the comparison tests to favor gas…

Thank you Harald for your testing methods and results, outstanding.

Take a look at Tony Beasley's results of his testing made a few years ago here on BPL.

http://www.backpackinglight.com/cgi-bin/backpackinglight/reviews/display_reviews?forum_thread_id=20958&cat=Stoves%20-%20Alcohol&cid=18

Tony has found that "slow" is better when it comes to efficiency.

Sgt. Rock updated his figures. He said:
(quote)
***Note – I have had to modify this report on August 31, 2002. I used some incorrect data on volume and weight of alcohol in the initial report and have gone back through to fix this*

http://hikinghq.net/stoves/stove_compare.html

You're welcome, Harald. I wish I could claim some great insight, but I'm afraid the choice of measuring the fuel by weight was more one of practicalities. Firstly, I can measure the weight much more accurately than the volume. Secondly, I was trying to get some idea of weight of fuel needed for different length trips with various stove set-ups, so I can choose the best combination of stove + fuel weight for any particular trip.

Will the Starlyte stove burn as well at ALL altitudes as the Trail Designs 12-10 stove? TD did a lot of testing to arrive at their design.

That is an important question, Eric, at least for those of us who camp high up. It's going to be at least a couple of months before I'm up above the treeline, and I certainly won't be carrying weighing scales and spending my time watching pots of water boil. Is there anyone living at high altitude with a Keg-F and a Starlyte who fancies a bit of testing?

Yes, it will burn as well if not better. The flame of the StarLyte stays focused under the bottom of the pot as seen in the videos of the under glass experiment.

Altitude and alcohol burn the same in all stoves as long as the oxygen input holes are the same. The StarLyte has a more controlled release of fuel due to the internal design. The 12-10 is more swooosh and burn type of burner, that's why the faster burn times. Once the 12-10 gets heated up it burns in a radical fashion and becomes engulfed in flames. we see photos of well used 12-10's that are completely annealed and disfigured. Still usable, just an observation of how the burner functions under the cone. For the next week I'll be on a camping trip with my wife and will do extensive burn tests with the StarLyte burner under the cone to see if annealing occurs.

As we all know, windscreens help focus heat and prevent wind from removing heat from our pots. A vertical windscreen is as good as a cone shaped. The unique thing about the Caldera is the fact it supports the pot.

I have the cone for the keg, no other cones.

Eric, what have you experienced with your cones and use of alcohol to boil 2 cups? How much fuel used to boil 2 cups and at what altitude?

The basic design of the cone has changed since the original. Design change came about due to structural failure of the locking mechanism. The hole placements seem to have also changed performance.

Dan, I have been doing a lot of testing recently of the Starlytes and the 12-10, and most of the tests bare out what you say. The Starlytes heat more slowly but more efficiently.
What has been surprising has been the Starlytes in the Cone for the Keg. They maintain their efficiency, but the speed of heating is boosted so much that the standard Starlyte is even faster than the 12-10. I'm not sure why this should be, but I like it.
With a 1" shim and a sheet of aluminium foil underneath, the standard Starlyte heated 400ml of water from 17 degrees C to 98 degrees in 6mins 49seconds using an average of 10.92 grams of denatured alcohol. The modified Starlyte did the same in 8mins 33 seconds on on 10.25 grams. The 12-10 used 12.79 grams and took 7mins 8seconds with the aluminium foil, and 12.49 and 7mins 48seconds without the aluminium.
The Starlytes and the Keg-F Cone work great together.
Incidentally, the Starlytes are also incredibly efficient with the Titan-3 windscreen, but don't get the fast boil times. The Titan-3 has disappeared from your website; will it be coming back?

Eric, TD has both the Modified and Regular StarLyte burners in their possesion. They might be testing them at different altitudes as we speak/write. I'd love to be able to travel and do the testing for you. As time goes by, we'll get more results of altitude testing during this coming hiking season unfolds.

William, when I return from a week of camping, I'll list the Titan-3 titanium windscreen/stoves by themselves. I have 6 left. The stainless steel pot supports are now listed separately. I need to find a different supplier for the Ti before I proceed with another batch.

If we look inside the top holes of the Caldera cone we can see the Foster pot is about 1/4 inch away from the cone. When we apply the same distance with the Titan-3 windscreen we get great results using the StarLytes. Verticle windscreens have been working well with stoves for years. The Ion stove(Sgt. Rock) being one that worked well under confined conditions with verticle windscreens. The Ion was made with the same container as the StarLyte. The Caldera Cone was spread out at it's base for greater stability. There are a lot of stoves that have not been tested under the C Cone and may vary well work just fine. One person reported using the Venom Super Stove and it worked well.

"So, do you need to raise the stove, or can you just drop the pot?"
Ideally you cut the cone down so the pot sits at the right height. The saves weight and the cone packs up even smaller, thus freeing up more pot space for other items. Raising the stove/dropping the pot is a good way to experimentally achieve the right height and it's fine to do long term if you'd rather keep the option open to go back to the 12-10.

The dimensions of different Sidewinders vary, but in short you want your pot roughly 1.8 – 2" off the ground with the Starlyte (I don't have my numbers in front of me, and it does vary a little cone to cone since diameters/cone volume varies). I think the smaller Sidewinders (0.6L) position the pot a bit high even with the stakes gone, so you need to jack the stove or trim the cone, the 0.9L sidewinder is a bit high too, while the 1.3L puts it pretty close to ideal or a bit low and the bigger sidewinders MIGHT put the pot too low without the stakes.

"What has been surprising has been the Starlytes in the Cone for the Keg. They maintain their efficiency, but the speed of heating is boosted"
Interesting. I suspect what is happening here is that in the smaller cone, the Starlyte stove is getting hotter which increases the rate of fuel evaporation and thus we get even more fuel being burned (even hotter still) until eventually it reaches an equilibrium (or achieves a melt down). Dan/Zelph, have you ever gotten a Starlyte so hot it runs into problems? I wonder if there is any danger of approaching the temperature limits? If not, some sort of device that reflects tons of heat back on the stove (ie. sort of an inner cup) might lead to really fast boils (and faster fuel usage).

Dan, I can understand stoves getting hotter and faster fuel evaporation leading to faster/hotter burning. I've read several threads (about other stoves) where this appears to happen. However, it always appears to be accompanied by higher fuel use. What I don't understand is that with the Starlyte in the Keg-F cone, fuel consumption decreased.

Fair enough – that is surprising.

First off, it is a well-designed stove. You are correct in that when alcohol stoves are in a hotter environment, they tend to vaporize faster. That being said, faster vaporization doesn’t always lead to inefficiencies. In my experience, wick based stoves tend to throttle the vaporization rate a bit (in the direction of goodness). If the flame pattern spreads larger, but still remains small relative to the pot diameter you are good to go. There is also the thermal integration with the long skinny pot inside the tall, skinny cone. Weird things can happen at the system level. My 2 cents – Jon

http://hikinghq.net/stoves/stove_compare.html

I believe that stove comparison could use an update, I am easily able to not only match, but exceed, what sgt rock reports for not only his cat stove, but (by far) the pepsi can stove he used, in my current testing, and that's with a simple penny stove that takes maybe 20 minutes give or take to make (how to will be forthcoming). And this is with narrow pots, not wide. A 900 ml and a 750ml, the 750 is slightly wider and squatter than the 900ml.

I'll post more complete results later, but this AM, for example, outside, with a real wind, not stove fan updraft, I was able to get a 17.5 ml boil of 500ml with over 1 minute of boiling, rolling, with a new pepsi can stove I tried this morning.

Last night, in tests, I got to 99.5C/211.1F temperature, not quite 100/212, but pretty darned close, using a digital deep fryer thermometer. Outside temp about 16C, water temp 25C, roughly.

I haven't yet tested minimum fuel to boil 500 ml in this latest pepsi can stove, penny style, modified, but it looks like 15ml would not be far off the mark, ie, 11.4 grams, ie, 0.4oz per 500 ml boil, which is only .1 oz per boil difference from gas cannister stoves from what I gather, give or take.

However, I am also finding that the height of the windscreen, when there is wind present, ie, real world situation, not indoor test, is very important, a 4" screen just does not cut it, a 5" one does ( assume there's a wind vortex or something that forms and goes down to the flame area at 4", but not at 5", not sure yet), with same stove/stand, slightly different pots, and wind screens 1 inch difference, it's interesting to see the differences, it's between a full boil with 1minute of boiling to not quite reaching a full boil at all, not sure why or what the actual difference is, I'm going to pursue that a bit more fully to see if I can pinpoint it, the shorter screen goes with a very thin walled stainless steal pot I found, so it may be a difference in how heat is reflected back to the stove, I"m not sure yet.

For economies sake, I am using slx, but for heaven's sake, do NOT use this stuff indoors, I consulted with a real chemistry professor, and he said students are not allowed to even open methanol without using the enclosed, ventilation fan running, toxic chemical handling boxes, whereas of course, ethanol is just fine. So the somewhat glib assumptions of safety re handling high methanol content fuels like HEET/slx might be worth a thought if you care about your health.

Re the cone holding up the pot, in early tests last year, or the year before, the heat would slightly deform the screen, and make getting the pot out a real challenge, which is when I stopped using method, I like to be able to lift the pot out easily, without having to get the screen off. That's when I decided to go with the straight screens, I'm suspecting that what is wrong is not the cone/no cone shape, but rather simply too short straight screens, which are too far from the pot walls, ie, diameter is too big. I'm using, after a lot of testing, pot diameter + .8 inches screen diameter, ie, a .4 inch gap. This can be easily tested however. But I have been noticing 4" screens being sold, and in my opinion those are too short, and will cost you far more in extra fuel consumed than they will save in weight.