Jan 27, 2007 at 5:59 pm #1221465
I'm wondering if any of you have chosen to try and duplicate the 'flux ring' on the Jet Boil pots; on any of your previously owned pots/cups?
If so what material did they (JB)use? And what can I use?
Adhesives or weld?Jan 30, 2007 at 7:22 am #1376371
@zydeholicLocale: San Francisco Bay Area
Is this the heat exchanger you're talking about? The corrugated ring at the bottom of the cup?
I'll just assume it is, and run off at the mouth here.
Since its attached to the cup, and I think the cup is aluminum, it is probably aluminum too, to prevent dielectric corrosion.
Its going to be hard as hell to duplicate that ring's performance unless it is welded/bonded to the cup.
Another thing to look at is the heat exchanger ring put out by MSR. Though large, it is corrugated and clamps around the outside of the pot.Jan 30, 2007 at 7:49 am #1376373
@jjpittsLocale: Midwest US
I have put a LOT of thought into this and have decided… that I need to put a LOT more thought into this. I think making the ring would be fairly simple but attaching it to the bottom of the pot in such a way that you get good reliable heat conduction is another matter. I am left wondering if there aren't other ways to accomplish the same thing. In the end doesn't this just basically increase the surface area of the bottom of the pot that can capture heat?
That MSR heat exchanger clamps on. I am thinking that might be a good place to start, although the MSR setup is very bulky.
There was a person that posted here the other day about there "Jetboil" like setup. Certainly worth looking into.
I have this Jetboil pot and it does work well, although I have yet to do quantitative testing with my alcohol stove.Jan 30, 2007 at 10:18 am #1376392
Bill FornshellBPL Member
@bfornshellLocale: Southern Texas
I made a couple of Flex Rings just after the JetBoil starting selling. Today you can just buy a pot with the flex ring made on it.
Buy a pot with the Flex Ring made as a part of it.
Jan 30, 2007 at 2:11 pm #1376432
Woubeir (from Europe)BPL Member
nice design. I just wonder, how did you design this fluxring? I have been thinking about this since Jetboil came out whit this but my main problem is finding the right material (unbelievable how hard it is to find some materials overhere in Europe). I guess you start with a circular piece of aluminium flashing. What is the diameter of that piece and what is the diameter of the end result?Feb 2, 2007 at 11:51 am #1376893
Looks like what I was asking about Bill. I too wonder if the first 2 photos, and the last; are'nt the same ring? The last one that looks burned, has some kind of edge around it's perimeter?
I wonder if the Jetboil pots are AL, as Dwight suggests the ring and pot are? I thought it was Ti?
Did you get the FedEx box I sent down a few weeks ago? I think I included a Brochure on a welding rod for AL in it. Is that a Cascades Design AL pot?Feb 5, 2007 at 2:04 pm #1377223
I have also been doing a lot of thinking about flux rings and I suspect that the flux ring has two purposes, the first is to improve the heat transfer by increasing the surface area of the pot that is in contact with the hot gasses and therefore transferring more of the heat to the pot and the second is to slow down the dwell time eg: the time the hot gases spend on the bottom of the pot therefore also transferring more heat to the pot.
As I understand the Jet boil pots are Aluminium, which has by far the best thermal conductivity of all of the materials used in backpacking pots, some initial testing which I have done to try and work out what is the best pot material has shown the this can also be a negative as while it is the best at transferring the heat from the flame it is also the best at loosing the heat from the sidewalls of the pot. Jet boil have over come this by insulating the pot with neoprene rubber.
Jet boil stoves have also increased efficiency by making the adjustable flow valve that does not allow the burn rate to be set to high. My testing has also shown that with all three main fuel stoves (canister white gas and alcohol stoves) that operating the stove at to high a burn rate is inefficient.
It is these three improvements that I think make the jet boil stove as efficient as they are.
TonyFeb 6, 2007 at 4:09 pm #1377350
Good points Tony, along the lines of what I have been pondering for some time. Then insulating a Ti pot would'nt be as efficent if it does'nt lose heat from the sidewalls at the same rate?Feb 6, 2007 at 7:09 pm #1377373
A good point. Insulation on a Ti pot would probably not have as great an improvement on efficiency as it has on Al pot but any side wall insulation would improve the efficiency of any pot at the more efficient burn rates. At less efficient high burn rate it is another story.
I have plans to do test what effect insulation has on a pot some time soon.
TonyFeb 6, 2007 at 8:20 pm #1377376
Adam KilpatrickBPL Member
@oystersLocale: South Australia
Has anyone tried to make a neoprene insulative cover for a Ti pot/mug, like the new Firelite 500? Without a flux ring on the bottom will you just end up melting it with licking flames from the side?
Will be good to hear how you go Tony!Feb 6, 2007 at 8:27 pm #1377378
..The snowpeak cups, such as the widely used 600ml, do not come with lids. A reflectix lid extending about 1" down the side of cup would serve as an insulated lid, and provide a little insulation without getting close to the flames. With a rubber band it could help to keep stuff in the cup. Ill try it soon.Feb 6, 2007 at 9:42 pm #1377388
If the burn rate is not to high then the gasses coming up the sides are not that hot, below is graph of the temperature verses time (blue line) and the red line in the hot gas temperatre about 1cm from the pots side wall about 1.5cm from the bottom. note that the temperatre is only about 40ºC but at higher burn rates the temperature can get above 200ºC. Most insulations probably could cope with 40ºC
This test was boiling 500g water from 20ºC to 95ºC in about 12 minutes 20 seconds
TonyFeb 6, 2007 at 9:58 pm #1377390
Tony, great test setup you have there; and very relevant info. Evidently reflectix can tolerate up to 82'C with no damage, and up to 121'C for 90 hours[1,2] so a reflectix lid could extend quite a ways down the exterior of a cup and theoretically decrease boiling times and decrease fuel consumption. I think we have figured out a useful application, and you certainly have the setup to verify it.
If the lower half of a cozy were designed to join the upper half/lid with no overlap, you've got a very light setup for simmer cooking in any size pot. Especially useful for tall (inefficient) pots such as the snowpeak mini solo.
As Adam suggested, neoprene would work also; its service temperature limit is 95C
 http://www.mfa.org/_cameo/frontend/material_print.asp?name=neoprene&type=descriptionFeb 7, 2007 at 12:58 am #1377395
Thankyou for the information on neoprene/reflectix and the compliment on my testing setup, I have spent several years setting it up and a lot of money,it has been financed out of my own pocket as is the stoves and canisters that I use, although some of the equipment/computers are old discarded equipment that I have been lucky enough to acquire or borrow. Time is my biggest problem at the moment with my testing and development program.
I have not heard of reflectix before I will see if it is available in Aus it sounds as if it is interesting insulation, neoprene is heavy and it adds quite a bit of weight to the jet boil pot which is one reason the UL people do not like the Jet boil that much especially for short walks. Jet Boil stoves have just become available here in Australia and I hope to purchase one soon, I think that they are a great little stove which has progressed the design of backpacking stoves more than any stove has for a long time.
TonyFeb 7, 2007 at 1:23 am #1377396
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> Jet Boil stoves have just become available here in Australia and I hope to purchase one soon, I think that they are a great little stove which has progressed the design of backpacking stoves more than any stove has for a long time.
Ah … read the reviews.
They are very heavy, lack power (by design), die totally in the snow, and only work well with new isobutane canisters on warm days. Yes, they are more efficient, but do the maths and work out what the real weight savings in fuel are and what duration trip would actually justify the extra weight (and cost) of the heavy stove plus heavy pot over something like a Snow Peak GS100 and an AGG 2 qt pot or an MSR Titan 1.5 L pot.
Note that the package weight they quote is usually for a 100 g canister, not a 220 g canister.
(These comments are based on my experiences and do not reflect any official BPL position.)Feb 7, 2007 at 1:44 am #1377397
Reflectix is a radiant barrier which is commonly used in the backpacking community in cozys, such as by http://www.antigravitygear.com
Our discussion started with lids for cups and other pots; the jetboil is already insulated, and might not benefit much by reflectix. With all due respect to Roger, yes, do read the reviews on the jetboil. It has all the limitations of a canister stove naturally, but there are reasons it is a popular stove among the lightweight crowd (not the UL crowd?) I have a jetboil, and every guy I've hiked with lately wants one as well after seeing it in operation. I can have a hot drinks for 4 people three minutes after taking it out of my pack; while holding it in my hand if necessary at a rest stop. As Roger mentioned, it is 'low power', lower BTU output than other stoves. That is by design. It is a tradeoff of speed and fuel consumption. There is no reason to pump out more BTUs than the flux ring can absorb. I think they dialed in the BTUs well, since I can literally hold the metal ring below the neoprene while the stove is running.Feb 7, 2007 at 2:22 am #1377399
Of course I have read the reviews on Jetboil stoves and I understand the negatives about weight and the problems with upright canisters stoves in cold weather but all stoves have there good and bad points, I still think that they are a great stove and Jetboil have made other manufacturers look at their designs.
I also currently use a much lighter stove pot system MSR Pocket Rocket and a Snowpeak Ti pot but it is not perfect does not work in the cold and has very poor efficiency in the wind, as Brett has mentioned the Jetboil is a quick easy to use stove in a fairly large range of conditions.
TonyFeb 7, 2007 at 9:39 am #1377434
Tony, you and Brett made some relevant commnets here that sparked an idea in my mind.
What if we constructed an 'upside down' cozy for cup or pots from Reflextix (aluminized bubble wrap)? My idea is that it could serve as the lid, upside down on the pot or cup; and when 'right side up' placed on the cup or pot removed from the heat. Cut a slit in the side for any handles.
Also, I noticed a foam sheet product at a local craft store called, 'Foamtastic' from http://www.nicolecrafts.com, in a 9" x 12" x 1/8th" +/- thick for .49cents. Not sure of any of it's other qualities other than it's waterproof, seems like it would be insulative though.Feb 7, 2007 at 4:20 pm #1377498
I like your idea of a reversible cosy/lid it solves two problems with one cosy.
I was reading an article last night in yesterday’s local paper about how our historic High Country Huts are burning down due to the high incidents of drought fuelled bushfires that we are currently experiencing. The High country Rangers are experimenting when a fire is nearby they wrap the huts in what we call sarking a form of heavy duty foil insulation for houses to try and save them. For some time I have been thinking about a light weight pot insulation idea and reading the BPL forum and reading the Huts article has helped me with an idea
I have been thinking for some time of a design some thing like your upside down cosy but with a small modification instead of having a tight fitting side why not have it loose fitting with about half inch (12.7mm) clearance to trap the hot gasses around the pot. See picture below, this is a pot lid side wall insulation cover that I made this morning out of Aluminium foil and it weights 6.6g (0.23oz). I have not tested this idea yet.Feb 7, 2007 at 4:24 pm #1377499
Sorry wrong picture came through try this one
TonyFeb 8, 2007 at 10:54 am #1377623
Tony, yes, that's what I am thinking. I thought of making the cozy 3/4th's the depth/height of the pot/cup. This would save weight and prevent it from catching fire if flames licked up the side on a flaring stove (if made from Reflextix).
Foil seems to require too much care to me in the field to be durable for the long haul; but I may be tougher than you on gear. Maybe a foil formed bowl, one already sold, would have thicker AL and be more durable? It could be trimmed/crushed down as needed to conform to the bowl.
That said, if the purpose of the cozy is to be 'heat retentive' then which material(s)work in this regard? Reflextix bubble wrap, HD AL foil, foam, neoprene; for the weight? Ahem, Mr Nisley,Bill F, anyone else with more specs' than i care to chime in here?
Cool stove in that first post's picture Tony! Nice flub!Feb 8, 2007 at 1:57 pm #1377643
I think you are right with the foil not being durable enough for long hauls. Reflextix is available here in Australia and I will be trying to get some soon to evaluate it, in the meantime I am going to test foil and sarking.
With the first picture the stove is proto type of a stove that I am developing from an idea that I read about by an BPL articles by Roger Caffin.
Selecting a Canister Stove for Cold Weather Backpacking
Part I: Stove and Fuel Fundamentals
Selecting a Canister Stove for Cold Weather Backpacking
Part II: Commercially Available Canister Stove Systems
My latest stove is one of the stoves featured in : Do It Yourself Projects to Reduce Canister Stove Weight
I am currently developing another cold weather bottom feed canister stove that I hope to have finished soon. This new stove is one from an idea that Roger suggested that I try in some correspondence with him last year. If the idea works then I will develop a lightweight version using aluminium and titanium.
Here two pictures othe first is a cold weather ideas prototype and the second is of my last stove.
TonyFeb 9, 2007 at 7:49 am #1377768
Okay, so this is something I've looked at in the past and I've gotten some product samples way back when but can't remember what company I got them from… point is, there is a 'neoprene-like' substance that uses silicone as it's base material and is flame resistant and temp resistant up to like >600 deg F
Silicone Foam is the general name of the material (I think)….
SNAP! I found the company in my email… CSHyde… I still haven't gotten around to playing with the samples…Feb 9, 2007 at 8:00 am #1377771
Eric NobleBPL Member
@ericnobleLocale: Colorado Rockies
Thanks for the link! This may just be exactly what I want for a cozy. Lets us know when you've had a chance to experiment with your samples.
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