Caldera Cones – My Adventures in Improving the ULC system

[Dan @ Durston Gear]

Nothing new to really add here…I just wanted to follow up on this thread and say how I continue to be extremely impressed by this setup. A bunch of small changes have added up into a system that is lighter, simpler, more space efficient and quicker to use than other cones.

Pros (over most other cones):
– stove lights easily in winter
– fuel can be stored in stove via lid, no wasting
– cone stores easily in the pot without consuming any volume (like the Sidewinder does)
– no fry pan lid required for cone storing inside pot (a la ULC)
– lighter due to carbon lid, lack of stakes etc.
– extremely quick to setup with no stakes
– efficient due to depth of pot + short stove enabling good (high) cone coverage around pot

I can store a small fuel bottle, stove, spoon and mug all inside this pot in addition to the cone. Simple + efficient = elegant.

Weight is down to 124.8g all in:

Pot + Carbon Lid: 82.6g (2.9oz) – lid not shown
Cone: 25g
Starlyte Stove w Lid: 15g
Silicone Band: 2g.

[Rod Lawlor]

Hi Dan,

I wonder if you might have similar functionality by ditching the handles, and going back to your full width silicone band? The wider band would/should give you a decent grip, and be about 10g lighter than the handles.

Rod

[Dan Yeruski]

Sweet set-up Dan. Trial and error really worked well for you.

Some good news. I have located a source for caps/lids for the StarLyte burner. I've increased the height of the burner so it can now hold 1.5 ounces of fuel.

I just completed testing some sheet cork on an experimental set-up yesterday. Cork is light weight and very insulative. Much better than silicone bands. In my video I show large pieces used for the experiment. I will reduce the cork pieces to tabs of the appropriate size for the next phase of testing.

You can ditch your handles and replace with cork tabs or band to make your set-up a little lighter. I can send you some sheet cork to experiment with and will also include some new lids for the starlyte. Send me your address and I can get them in the mail today or tomorrow.

This is the video I loaded to youtube yesterday:

http://www.youtube.com/watch?v=5m7ul-zaCqw

You've done a fantastic modification. Keep it going, add the cork, nothing ventured, nothing gained :-)

.

.

[todd]

Hi Dan,

Still no concerns about melting the silicone band?

If not (Zelph's cork idea shakes things up a bit) then I think I like your setup more and more as time has passed.

Like I NEED another Caldera!!!!!!!!

[Dan @ Durston Gear]

"I wonder if you might have similar functionality by ditching the handles, and going back to your full width silicone band? The wider band would/should give you a decent grip, and be about 10g lighter than the handles."

Very interesting idea. I never thought of making the silicone band serve double duty as the handle/grip as well. The pot handles weigh 17.9g, so there's quite a bit of room to come up with something lighter and possibly better. I wonder if two thin (ie. 1g ea) silicone bands (very grippy) sandwiching a thicker (ie. 1") cork band would be about ideal to create a light but usable grip. This could save weight and slightly increase efficiency by acting as sort of a pot cozy for the portion of the pot that protrudes above the cone.

"I just completed testing some sheet cork on an experimental set-up yesterday. Cork is light weight and very insulative. Much better than silicone bands."
Wow the neat ideas never stop coming. Unfortunately I can't view that video right now because I'm away for the next 2.5 weeks working a remote geological camp with super slow internet (and YouTube blocked). Accordingly, I'm not quite understanding how the cork is used. Can the cork withstand the heat like silicone can and thus replace the silicones role? Or is it used in addition as a handle/gripping surface? How are you attaching the cork tabs to your pot? And how do you join the cork to form a band? Sorry for the barrage of questions. Address is sent.

"Still no concerns about melting the silicone band?"
Nope….no signs of any trouble thus far. I've got about 25 boils on the band and I've used it with ethanol now which burns even a bit hotter. I don't know for sure I won't hit trouble down the road, but if I'm on the trail when it happens I can easily use tent stakes for the duration of the trip. Nice to have that backup.

My cone does fit quite snugly around the pot and then the band basically seals the top of the cone to the pot, so I don't get any flames or even hot air sneaking out of here. The silicone doesn't even seem that warm. If I did have a cutout for a pot handle then it's possible I would get hotter air/direct flame touching the band which might then pose problems. Ultimately though, I think the silicone is a successful solution because I have ample cone coverage up the sides of the pot that keeps the silcone higher than the flames ever reach. My tall/narrow pot + short stove gives me several inches of cone coverage up the sides of the pot. If someone tried to do basically what I've done but with a shorter cone (ie. using a shorter/wider pot) then the silcone band would be lower and thus more likely to get too hot. The ECA278 pot seems to be an awesome shape, although other pots would work as well or better (ie. MLD/Ti Goat 850ml) if you commit to the ditching the handles and order a custom cone with no cutout.

[jason quick]

…. having the cone, mug, spoon, fuel, possibly a light load towel (or part thereof) and stove all inside…..

….whoa! I have ULC cook-system envy.

….my wife is going to kill me, here comes another order.

[Eric Blumensaadt]

Or you could just get a Trail Designs ti Gram Cracker ESBIT tablet holder, use ESBIT or FireLite tabs and forget all about fussy alky stoves. Works great for me with my Sidewinder cone stove.

Just sayin'…

[Dan Yeruski]

Last time I checked, wide silicone bands get as hot as the contents of the pot. If you got boiling water, you got 212 degree silicone rubber to grab onto, right? thats too hot for my fingers. In my video you see the water boiling and I'm able to hold onto the unit.

The cork I sent you has a natural curve from being rolled up a few years. cut a band 2/3 the length of your pot diameter as wide as needed to fit your 2 pick up fingers. Use high quality silicone caulk as your glue.

Cork insulates. It will char when exposed to direct flame but does not ignite redily. Cork/bark insulates some trees from prairie fires, creating savanna type areas. Mostly the Burr Oaks survive.

The cork may work for you, maybe not. Try it.

[Dan @ Durston Gear]

Thanks Dan for sending that. I'll give it a shot for sure.

[jason quick]

Hi Dandydan

As I mentioned in an earlier post, I really liked this concept, so I followed your lead and tried to apply this to my own gear before breaking the piggy for another purchase.

I turns out that the Evernew 600ml short & wide pot that I purchased with my sidewinder Ti-Tri kit sits almost perfectly at the same height (under normal Esbit set up) as it does if it were placed on the Starlyte stove with pot stand. If I recall from my own measurements, I think the height from stove differed by approximately 1 to 2 mm, or 0.08 inches….close enough for me. With the sidewinder cone rolled up inside my Evernew 600, I can still get the stove and a Bic lighter, along with the cone inside the pot without modifying a single thing. Plus, I have the benefit of nesting the stove all the way down into the cone as per the original intention, maximising efficiency.

So, in line with your goals, I now have a stove that requires no priming, fits inside the pot, which also fits the cone…awesome.

So I tried to take this a step further, and see if I could fit some fuel in the pot also. After looking at every plastic bottle in every isle in my supermarket, I managed to find and purchase a small Listerine bottle (80 or 100ml I think…I’ve forgotten…however it is the same shape as the large bottles with a safety cap) up inside the cone. This worked….perfect…just enough fuel for either a quick overnighter/two day adventure. The measuring cup can also sit upside down on the cap of the fuel bottle too, inside the peak of the cone.

So…the approx. weight at this stage for pot with original lid, cone, Starlyte stove with lid = 135 grams.

Excellent…good enough for me! Although…my lid weighs approx. 30g, so if I could find someone to make a carbon fibre lid in place of the original, I reckon I too could knock off a little more.

The last challenge was to find a cup that could fit in the pot also. Well, I stumbled across one of my daughters sippy cups (she is 1…and I don’t think she was that attached to it anyways ☺), which fit well after having to cut it down a little (besides, I love being reminded of my kids when out camping…and can't wait for them to join me one day soon). I can still obtain a 1 cup measure (Australian cup = 250ml) after the cut down, which equals a normal cuppa tea or coffee for me. However, I did this with ONE slight modification…I had to take an approx. 1-2 mm shaving off the top of the cone. I had to do this to compensate for the greater circumference of the cone with fuel inside and base of the cup to fit inside the pot. This slight modification brought the height of the pot above the Starlyte stove to the same height as the Starlyte pot stand anyway…so it worked in my favour!

Done.

I also made up a cozy base and lid to fit the pot

So, now, I have an original sidewinder caldera Ti-Tri from TD made for the Evernew 600 (current base weight of 135 grams), which retains its original efficiency by sitting completely inside the cone. Plus, it is a wider pot with good surface area for heat exchange. I am obtaining similar burn/boil times as you, however I think, like yourself, have to add a few holes around the base to improve combustion.

Plus, having the Ti-Tri, I still have the option of esbit (which worked awesome in the Aussie Alps with a 40 knot wind the other day, or wood burning if I wish.

Anyways, just thought I’d share. Thanks for being ‘open source’ with your idea Dan.

Jase in Australia

[Dan @ Durston Gear]

Wow that's some excellent work. I never thought about applying this short stove idea to the Sidewinder concept. That's awesome that you've managed to ditch the pot support altogether (even simpler and lighter than my silicone band) and still get everything to fit inside the pot. Plus you get max efficiency with the whole pot in the cone and you get max stability with a setup this wide and low. It's perhaps the perfect setup in the 600ml size class. For me 600ml is a bit small (750ml is already a bit of hassle and I'd prefer 900ml) but it all depends on your individual cooking style.

It seems like there might be some more pot options out there that this would work for as well….basically any pot where the width is at least 2" greater than the height would allow for a cone that stores in the Sidewinder fashion, and sits directly on the cone at a height ~1.8" off the ground.

What is the silicone band around the cup for? Just a way of holding it with hot fluids?

So I guess the big question left is: How does it burn? If your pot sits slightly low then you may need some supplementary holes to get proper air/fuel mixing. Did you find you get good boil times and fuel efficiency? Or do you think you'll need to add a few holes around the bottom perimeter?

---

I got the cork from Dan/Zelph a couple days ago and I agree with him that's a promising concept. It appears that quite a nice pot grip/support could be fashioned that is lighter and nicer to use that the original handles while increasing efficiency due to its insulating properties.

I don't have any silicone caulk on hand, but I do have some SilNet silicone tent sealer that I think will function similarly. I'm going to see what I can come up with in the next few days.

One idea I had is that perforating the band of cork with hole punch sided holes may allow for a generously wide band that keeps the users hand off the bare metal while reducing weight and perhaps allowing better adhesion.

[jason quick]

Hey Dan

That's for sure, a neat discovery. :-)

You're right, the silicone band is merely to hold the cup…it gets quite hot. Unnecessary though, and adds weight. By the way, I can fit my folding spoon in the pot too. I've always used a long handled titanium spoon, but purchased a folding titanium spoon yesterday…fits like a charm!

My only concern when I shaved a couple of mm off the top of the cone was not so much about the height above the stove, as I knew I had a few mm leeway/buffer (in my favour) in the first place. It was more to do with the fit of my stove around the cone. Taking any of the top of the cone would inevitably increase the diameter, so I was concerned that it would become too large. However, it fits well. It is not super snug, however it never was…it still locks in really well around the rim of the pot.

As for the burn figures…still more testing to do. I must put in a disclaimer though, my measurements are not as accurate as yours, so all of my figures are as close as I can get at this stage.

I did some testing yesterday….

TEST BATCH 1:
Ambient temperature of 13C/55F
500ml of water (2 Aussie cups)
Water temp of 13C/55F

3 test times below:
1. 9:15, 2. 9:13, 3, 9:05.

TEST BATCH 2:
Ambient temperature of 13C/55F
500ml of water
Water temp of 15C/60F

3 test times below:
1. 8:08, 2. 8:00, 3. 8:10

For the warmer water testing (test batch 2), I managed to use no more than 20ml of Ethanol (95% Ethanol) each time. On two of these tests I used approx. 17ml of fuel. As long as they don't exceed 20ml under those conditions then I'm happy.

…yes…small sample sizes, and perhaps the figures are not as efficient as they could be…but for all intents and purposes, I am happy at this stage. Like you, the benefits to modifying the set up was not all about burn times, but convenience and weight as well. Plus, these test burn times are similar (actually better) to what I was getting prior to the mods anyway.

Side thought….I wonder if Ruta Locura do custom CF lids?

That's about the extent of it thus far. I double checked my pot heights & levels, and my pot sits approx. 2mm (0.08") higher than the post stand provided with the Starlyte. For me, this difference is negligible. Despite this, I still believe I will have to place some supplementary holes in the cone to improve air/fuel mix. I may start with 4 holes….then move to 6 perhaps. I think this will make a big difference, just like you found.

Nice use & idea regarding the cork. I think the handles become more important with the short/wider pots when I consider the actual manual handling of the pot/ability to safely grip/hold the pot. The narrower taller pots would suit being sans handle much more.

I have one random question Dan, just curious as to why you prefer 900ml pots? …just like to learn more about your cooking/eating MO while I am here/perhaps I'll put it in a PM instead.

Cheers mate
Jase

[Dan @ Durston Gear]

Your results sound good to me. Before you go ahead and punch extra holes, you can somewhat simulate the outcome by creating an air gap under the cone to allow a bit more flow. Putting some tent stakes flat on the ground and setting your cone on that creates a gap that allows more air flow (and raises your pot a bit higher off the stove), so if it burns better like that then you know you need more air holes and/or more height above the stove.

Ruta Locura won't do custom CF lids. I asked a few months ago and the answer was no. That's why I choose my pot with their lids fitting as one of the criteria.

Good point on the narrower pots being more suited to a cork handle than the wide ones. It also doesn't seem possible with the wide pots as none of your pot is exposed above the cone.

just curious as to why you prefer 900ml pots?
For breakfast it doesn't matter, I usually boil ~2 cups to make coffee and oatmeal (minute oats + brown sugar + nuts or dried fruit). I grab a few oatmeal add ons in the bulk section (dried blueberries, dried cranberries, almonds, currents etc) and then add a different one each day to keep things interesting. Lunch I almost never cook.

For dinner though, I cook quite a few meals where 500ml of boiling water is required, so when you add the food to the boiling water you end up pretty close to the rim on a 750ml pot. Not a big deal, but a little more capacity would be nice to make stirring foods and bubbling chili a bit easier to contain.

Also, when I cook dinner I like to boil 3 cups (750ml) and then pour off one cup for a hot drink before adding the food. With a 750ml pot, I end up boiling about 700ml and then struggling a bit to pour off one cup without spilling too much. So it's not a big deal, but an extra 1/2oz for 900ml capacity would be weight well spent.

[jason quick]

Hey Dan, thanks for the tip re. ventilation testing.

Shame about Ruta Locura and custom lids, although I totally understand. I guess the other option is for me to custom my own out of a heavier duty foil, although this could lead to issues associated with fragility…which is why I prefer the stronger Ti pots in the first place. Never mind. ☺

I do like your eating/food plan. For me, I prefer to not eat hot drinks with my meal – I prefer to boil/heat some water a little while after dinner for a cuppa. I say heat as opposed to boil as I find that the water only needs to reach 70’ish degrees C/160F for a nice hot cuppa…it doesn’t have to boil. I recall reading a thread somewhere years ago (I actually think it was on this forum…written by Roger Caffin! …writing to a thread about gas canister use in snow), which spoke of the exponential leap in energy required for heating when water changes state…. whether it be from frozen to liquid, or liquid to gas. Anyways, that said, the cuppa that I have after dinner would only really require no more than 10ml of fuel to get up to 70’is degrees C/160F (my last testing brought 1 cup of water to a boil even in just under 4 minutes with a fraction under 10ml…so I reckon even less could be used to get to 160F/70C.

But I totally get what you are saying, spills and mess created from an overflowing pot full of tasty awesomeness is annoying… I’d go as far to say it’s on par with peak hour traffic and finding car parks.

Sorry, I digress. ☺

I took your advice on how to determine whether it was just the fuel/air mix, or whether it needed to be higher off the stove too. So I did some more testing. I lifted the base of the cone AND the stove by 4-5mm (ventilation’s sake).

Almost identical conditions as previous test batch 2 from my other previous post…

Ambient temperature of 13C/55F
500ml water
Water temperature of 14C/60F.

Wow…boil times came right down. They went from averaging 8:06, to averaging about 7:30. This occurred over 4 test boils, and I was comfortably using down to 17ml fuel each time. On one occasion, I managed to hold the boil for another 1:45 seconds before flame out and loss of boil. The other ‘post boil’ times were less, averaging 50 seconds to 1:20 until flame out. All of these were done with approx. 17ml of fuel.

I then left the stove at bench height, and just raised the cone/pot for ventilation and increasing pot height. Boil times were even quicker (averaging about 7 minute mark over three test boils), however the fuel burned less efficiently as the time til flame out came much sooner after reaching boil, which may concern me in real world, colder climes.

So, I can semi-confirm now that the pot could do with some extra holes. Whilst it did burn faster when I increased the pot height, it was less efficient (which is what you determined in your comprehensive testing) plus, I’d have to modify my set up to make this happen…and it’s just not worth it for those very reasons.

So I will punch out some holes. I didn’t calculate any surface area equivalents (to determine how many holes), so I’ll just do it in stages I think….I just need to go buy a single hole punch now, can’t trust a double for accuracy. ☺

[Dan @ Durston Gear]

Nice research. I just removed a single hole punch from my triple hole punch to create individual holes. They're normally easily removable and then you can use just the single punch with the tap of a hammer.

Good idea with the 70 degree water. I'll give that a shot sometime.

[Ken Thompson]

I like my new one with the "booster cone" Same efficiency as the full size one in a ULC package. Rock on TD!

This is the set up I have been waiting for. I have been a very happy canister stove user up until now. This works great for me.

[Bob Gross]

Wow. I see a BPL sticker on the Garcia bear canister. I wonder how much weight that added.

–B.G.–

[Ken Thompson]

It's a Bareboxer, so lighter built in.

I really should not advertise BPL. I'll go take it off right now.

[Bob Gross]

You're absolutely right. I should have recognized it by the latch hardware.

–B.G.–

[Ken Thompson]

Dan, Did you try putting felt in the 12-10 burner?

No real weight savings without the sticker.

Nice compact kitchen.

[Bob Gross]

You can switch the scale over to milligrams.

Your sticker is black on white. It might be lighter in weight if it was white on black, or maybe a cut-out decal.

–B.G.–

[Dan Yeruski]

jason quick said: (Excellent…good enough for me! Although…my lid weighs approx. 30g, so if I could find someone to make a carbon fibre lid in place of the original, I reckon I too could knock off a little more.)

That got me to doing a little research and I came up with a way to make a pretty good lid by using some ridgelines for strength. I used tempered, anodized aluminum. The lid in the video link is 4 inches in diameter and weighs in at 4 grams with the lid knob which is most of the weight. It was hard getting my electronic scale to register a weight prior to adding the knob. Your lid weighs in at approx. 30 grams.

Give me the outside dimension of your lid and I'll make you a sample lid at no charge. You can do an evaluation for me on it's construction and useability for your needs. Give me all the pros and cons about it. Maybe I can furnish others with the service of custom, very lightweight pot lids.

This video link is private for this thread only.

http://www.youtube.com/watch?v=kYBMNYRX9qM

If you agree, send me your address in a PM.

[Rod Lawlor]

Hey Dan,

That is slick!

I'll shoot you a pm with an idea.

Rod

[Dan Yeruski]

Thanks Rod. I'll give your idea a try.

Eric Blumensaadt said:
"Or you could just get a Trail Designs ti Gram Cracker ESBIT tablet holder, use ESBIT or FireLite tabs and forget all about fussy alky stoves. Works great for me with my Sidewinder cone stove."

Oh My!!! Eric needs to try the StarLyte alcohol stove……..nuttin fussy about that one. ;-)

[Dan Yeruski]

I knocked off some grams on my kit today.

2 cup Foster potwith lid. New edition of the StarLyte burner that holds 1.5 ounces of fuel suspended and a stainless steel pot support windscreen that has the supports welded to the wall of the windscreen. As it stands it weighs 2 ounces.

Windscreen is welded in complete circle and folds easily in the middle to fit into the pot. When removed it pops back to a nice circular form. My Suluck screen stays in a kidney shape so I tried my hand at making one out of stainless steel. The Suluck pot support also stays irregular in shape so I eliminated a separate pot support and did the integrated thing by welding to the wall of the windscreen.

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