Chris is also kind enough to mention CCS in the latest edition of his Backpackers Handbook & links to us from his website. Bit of a closet stovie!
PAN TEST ON ETA PACKLITE Hi Jim You expressed interest on how the well PackLite worked. Snowgoose had sent me this link Gas stoves which included information on inverting gas cartridges which intrigued me. I did a series of tests on different pans on the Packlite stove with different pans and the results show that the subject of boiling times is a lot more complicated than it appears. The results appear to be nonsense but there is an explanation to the random times. I kept conditions as constant as I could whilst doing the test in an unheated garage with snow on the ground outside. Air temperature 36ºF Water Temperature 38ºF Quantity 1 UK pint (20 fluid ounces, 0.71 litre) The garage door was kept closed so there was no wind effect. The tests were done with the stove in a conventional mode AND repeated with the gas cartridge inverted. These pans were used for the test. From left to right they are:- 1 An upright anodised aluminium pan of a similar diameter to the Eta Express 2 An Eta Express pan 3 A plain aluminium pan of a similar diameter to the Eta Packlite and 4. 4 An anodised aluminium pan of a similar diameter to the Eta Packlite and 3 5 An Eta Packlite pan When I started the tests I had no idea that the order that the tests were done in had any significance but it does. The first line of the test results shows the order that the tests were carried out. The second line shows the boiling time achieved. The third line shows the fuel consumed to produce the test times. I used an ordinary wrist watch with a second hand to time the boiling. This created problems because I timed my placing the pan on the stove with the second hand passing 12 o’clock. Prior to that I had to light the stove which necessitated removing the windshield because the igniter is under the windshield. Basically my left hand had to use the igniter whilst my right hand turned the gas on. I then had to replace the windshield and grab the pan ready to put it on when the watch second hand passed twelve. Initially I thought that If I placed the cartridge on digital scales, zeroed the scales at the start of the test then took the minus reading at the end of the test I would get the amount of fuel used during boiling. This did not work as resting my hand on the worktop disrupted the scale reading. In the end I had to disconnect the cartridge and weigh it at the beginning and end of each test. I used one MSR gas cartridge for all of the tests. This distorted the boiling times. These are the results:- The stove performed well in conventional mode bearing in mind the air temperature during the tests. Superficially the boiling times are nonsense. If you compare the Eta PackLite pan with the Eta Express pan it appears that a tall pan heats quicker than a broad pan. However if you compare the Tall anodised pan with the Wide anodised pan the situation is reversed. This makes no sense. However if you look at the fuel consumed you will see that there is a pattern. The pans with heat exchangers used an identical amount of fuel to boil the water. If you look at the pans without heat exchangers you will see that they also used a very similar amount of fuel to boil the water. A gram of fuel is a very small amount and the additional 1 gram to boil the tall anodised pan may be a result of the scales rounding off the weight of the fuel to the nearest gram rather than a full extra gram of fuel being used in that test. Unfortunately when I did the tests I made a very basic error. The performance of a gas cartridge depends partly on air temperature. Lower temperatures prevent the liquid vapourising and as the temperature drops the gas production reduces. Superficially the air temperature had not varied so the results should have been consistent. However I forgot that when liquid gas vapourises into gas the temperature of the remaining liquid drops which reduces the liquids ability to vapourise at the same rate. Basically less gas was being produced per minute for the later tests. I should have used a new gas cartridge for each test to get boiling times which could be compared. The cartridges would then have been at exactly the same temperature so should have produced gas at the same rate. I had never used a conventional gas stove with an inverted cartridge until I did the these tests and I did not know what to expect. At the end of the test on the Eta Express pan I turned the gas off and expected the stove to stop burning. It continued normally. I had mentally recorded the boil time but was a bit panic stricken at the stove behaviour. I think that I thought that the cartridge valve had jammed so turned the stove back on and off again. Nothing changed. I then realised that the fuel line was full of LIQUID fuel which would have to vapourise and burn off before the stove stopped. The fuel used in that test is distorted because of this. The panic may have affected my memory of the time taken to boil in that test. When I came to test 7 I realised that the gas pressure was dropping so worked hard at getting it back up. I then realised that might be distorting results so tried slightly less hard with test 8 and 9. I think that I had given up by test 10. If you look at tests 6, 7 & 10 you will see that those tests consistently used 2 grammes of fuel more that the same tests done with the stove in its conventional mode. I think that the 2 grammes may be the liquid fuel in the fuel lines which had to be burnt off after the stove had been turned off. WINDSHIELD I monitored the Packlite windshield during the tests. It remained cool when both Eta pans and the Tall Anodised pan were used so was solely acting as a windshield in that situation. It became hot when the wide aluminium pan and wide anodised pan were used so probably also served as a heat deflector with those pans When I had finished the tests on the PackLite I wondered how it compared with the Coleman Xtreme which is designed to be used down to about -20ºC. It gave the best boiling time but used more fuel I think because it has a bigger fuel line than the PackLite so more fuel has to be burnt off after the boiling was finished I hope someone has bothered to read to the end because this was tedious to write. Regards Bryan
I surely did Bryan. I also took Ross's view into account ... I wasn't inclined to be drawn into debate until I got this response from theyellowdog to my topic on the Sigg Firejet and it prompted me to investigate what I'd already heard was the puny performance of the Sigg I needed comparison stoves though, and with a free afternoon ahead of me and fuel to burn I launched into a group test. This group It was a calm, cool afternoon with barely a breath of a breeze and water temperature from an outdoor tap (faucet) was 50F (10 degrees Centigrade). I'd no stopwatch, but used an Ingersol pocket watch I've had since I was a kid, timing to the nearest fifteen seconds by keeping an eye on the second hand as the kettle came to a rolling boil. I poured a measured half litre of water into a small Primus Litech kettle for each firing, dousing the kettle in a stream water from the tap after each burn to bring its temperature back down before filling it. I used a windscreen to rule out as a factor whatever breeze arose from time to time. First off was the Sigg Firejet Followed by an Optimus 99 equipped with a mini-pump ... ... a Svea 123 (without a mini-pump Then came a Phoebus 625 burning paraffin ... ... my Primus 41 (silent burner) I gave CCS restoration topic 'Rustbucket' an outing too Then came three Primus 96's, a couple of oldies (1923, 1924) and a late Primus 96 from the Optimus era ... a Monitor picnic stove ... and a Primus 210 For good measure I rounded off with my Frankenstove, a British Army No.12 with an Optimus 111 kero burner fitted The results? Sigg 4 minutes; Optimus 99 4 minutes; Svea 123 3 minutes 30 sec; Phoebus 625 3 minutes 30 sec; Primus 41 3 minutes; Rustbucket (Optimus 111) 3 minutes; '23 Primus 96 4 minutes 15 sec; '24 Primus 96 3 minutes 30 sec; Primus 96 (Optimus era) 3 minutes 45 sec; Monitor picnic stove 4 minutes 15 sec; Primus 210 2 minutes 45 sec; Army No.12 frankenstove 2 minutes 45 sec. Ok, not a test incorporating much in the way of scientific rigour and going nowhere for the pragmatist who's not bothered about boil times anyway so long as they're fast enough. However, some themes emerged consistent with stuff that's emerged in CCS topics before. The Svea 123's a gem of a stove. No fuss, no pumping, it just went like stink. I personally share a preference with many stovies of thinking the 123 is a better performer than the 123R with the cleaning needle and in my simple test it beat the pants off the Optimus 199 with the cleaning needle set-up and a pumped tank. The Primus 41, with the silent burner at that, is a scorcher but the Optimus 111 is no slouch either. The welded stainless steel tank of the Army No.12 frankenstove, taking a lot more pressure than the brass 111 tank, gives an already excellent 111 burner design a turbo boost. Peculiar variation in the Primus 96's. I didn't expect that. It wasn't that the slowest was obviously off-form because I like to keep my stoves fettled to perfection as 'user' stoves, if not concours in the looks department. I expect it's down to microscopic variations in the lipstick burner orifices. Star of this test for me? The Primus 210. Stunning performance, simple, elegant, classic design. Oh yeah, the Sigg. What'cha mean, yellowdog, slow?. Ok, not the fastest, I'll grant. John
I think that is why there's been so much snow this year. With all the water that's been boiling we have a lot of extra moisture in the air these days!! I have to throw in my 2 yen on this one. There's been a lot of interesting information on this thread. Thanks to all those who have shored things up. I have to agree with some of you that it isn't all about boiling but simmering as well. The point is, simmering efficiency is just as important as boiling efficiency. If your car is not using fuel efficiently at freeway speed, chances are it won't be using fuel efficiently at low speeds, and so it is costing you money to run your appliance. Does it really matter? Maybe. Maybe not. If you want efficient get a stove that you feel is efficient and then follow the rules that HJ has outlined, one rule of which is using the windscreen. Of all the rules this one is the most important, then the type of pot used and then everything else follows. You'll save more fuel and costs than any other method and could probably use just about any stove, classic or modern. We're just not going to make the classics or new stoves run more efficient than their design unless you add some aftermarket piece to make it do so, if so, then boil times do not apply to the same brand. I do know from being in cold, sub-zero-F temperatures and wind, no matter what stove, that you will get faster boiling times and better simmering with a windscreen and good pot - hands down. Without these two components, it just doesn't happen and you always use more fuel. The rest of the rules only improve on this. One thing is for sure, once you run out of fuel, the hike and campout is over, especially on a cold one. What is the fastest boiling system out there? Does it really matter when you're camping and hiking? Not really, IMHO. As long as it is in the ball park of 5 minutes or less, and uses fuel efficiently, it works for me. 10 minutes is too long, something is wrong with the stove and/or fuel is being wasted - money out of my pocket. What does matter is the above plus the utility of the stove, the bulk it takes up in your pack, the weight you have to carry, and ease of maintenance on the trail. Car camping changes this slightly but some of the same factors have to be considered. Efficiency is one factor of many to consider. Shall I keep slinging manure? I hear a bunch of people out there saying, "YES!" ok, I'll stop. all the best to you water boilers!!! sam
Prescall you really must have pumped the snot out of that 210. Well mine are more of a 7min for a litre. and a 2 pint silent 5 min and about the same for a roarer maybe a bit less. I use boil times to see if my stove is performing up to the ball park " tea test" btu figures. Simmer abillities are different. If I am simmering something there are only a couple of stoves I use that I would leave unattended for any length of time. Opti 88 and tranny types. If it blows out etc no harm will be done exept tea will be a bit later!!! Barra
Hi This is the second time I have started this reply. I was part way through it when we had a power cut. I had just sorted stoves and heaters out when the electricity came back on. Unfortunately the power cut was the last straw for a tv digi box which has given up the ghost. I am not putting the stoves and heater away because I have a feeling that the power cable might get hit again by the contractor excavating for a new storm drain. I find maker's boiling time a complete waste of time and misleading. I used to assume that less fuel was likely to be used with shorter boiling times but this has turned out to be wrong. There are too many variables for the times to have any meaning. The water starting temperature. The air temperature. The wind conditions. The pan type. How effective a windshield is. Even if is is a close fitting foil windshield it will still be subject to periodic down draughts in windy conditions. I had several reasons for doing the tests on the Eta stove. It was 30 years since I had used a gas cartridge stoveAlp 7000 . At that time the normal gas cartridges contained pure butane and were a right pain. You could get "TRIAL" cartridges that had a small proportion of propane in them but I cannot remember them being a lot better. These Trial cartridges were difficult to find. I was curious to see if a modern gas stove was much better than the old ones. It was but I do not know if that is because of the stove design or because of the better mix of gases in the cartridges. I was also curious about the pans with the heater exchangers on them. They are definitely an improvement but not to the extent that Primus claim. I was also curious as to the stove performance when the cartridge was inverted. GAS STOVES With the tests that I did it appears that the amount of fuel used to boil an amount of water stays fairly constant with the Eta pans and with the other pans. Boiling times vary with the time taken to vapourise the liquid fuel into gas. This is affected by temperature. Whilst low air temperatures affect this function the vapourising liquid gas also chills it so it is losing temperature all of the time that the stove is burning. The affects of this chilling can be reduced by gripping the cartridge with your hands so that the cartridge absorbs some of the heat from your hands. With a remote cartridge stove the cartridge can also be shaken to increase gas pressure. I was surprised that this also works with an inverted cartridge. I do not know why it works but I suspect that it is similar to shaking a fizzy drinks bottle which releases some of the gas from the liquid. The inverted cartridge did improve the stove performance but unfortunately wasted about 2 grammes of fuel after the boiling had finished PARAFFIN STOVES I did some tests on paraffin stoves in 1995 or 1996. The main purpose of the tests was to calculate the amount of fuel for a trip. However whilst I was checking that I did some boiling tests solely out of curiosity. The 96 silent is a Special using a 96 tank fitted with a 2 pint silent burner. The Primus 210 silent is a 210 tank fitted with a 2 pint silent burner. The first test time for the standard 96 was 5 minutes. I repeated it and the next time it took 7 minutes. After that I stopped testing that stove as I did not think that results that varied so much had much meaning. I did test the 96 silent and it took 3 minutes to boil. The Veritas 1/2 pint took 14 minutes to boil and the Burmos 21 took 5 minutes to boil even though it should have boiled quicker than the standard 96. I suspect that it was probably an "economy" 21 produced after 1972. These were fitted with a 0.23 mm nipple instead of a 0.32 mm nipple in the belief that it would save fuel. Superficially the 96 silent would have seemed to be the more fuel efficient however this is wrong. The fuel used to boil 1 pint of water in the various stoves was:- Standard 96 0.183 pints (5 minutes boil) Burmos 21 0.225 pints (5 minutes boil) Special 96 0.245 pints (3 minutes boil) Veritas 1/2 pint 1.274 pints (14 minutes boil) It appears that boiling times may also be an unreliable indication of fuel consumption on paraffin stoves as well with gas stoves. Regards Bryan
Bryan, Thanks for posting all of your research. As near as I can figure from your various projects, the bottom line is to just use your stove, whichever one that may be. The results don't seem to vary that much if I've read correctly at least they don't for me. I'm not a backpacker, so I'll just take a gallon. Thanks again, Bob
Hey, Bryan and John, Great stuff, Guys, and very well done!! One questions, John: You mentioned that the 123 beat the pants off "the 199", but I'm guessing you were talking about the 99. Am I right about that? Also, all the photos, which were very well done, as usual, show the stoves completely surrounded by the foil windscreens. Did you actually use them that way, or was that just for show? I've always been very cautious about completely encircling any self-pressuring stove that doesn't have a remote fuel tank. I've long read that many a safety valve has been overwhelmed by that much heat directly on the tank. I actually did it once, myself, too. 8-[ Thanks, again, to the both of you Gentlemen, for the outstanding information!! Take care, and God Bless! Every Good Wish, Doc
No, Barra, I didn't. It was only half a litre I was boiling but it surprised me too, and the tank barely got warm (see my reply to Doc Mark, below) - well, it didn't have the time to get warm I suppose. Yes, Doc, I meant '99' of course. You're perfectly right about the encircling windscreen and the safety issue. I should probably have flagged that up as a 'don't do this at home' caution. The windscreen was used in that way nevertheless, which I reasoned was justifiable for the test session only in order to prevent stray breeze from becoming a variable and keep the boil times from becoming extended on a cold day. None of the stoves were injured and nor was the operator during the photo session. Seriously, the tanks didn't get warm in the four minutes or so each was 'in the spotlight'. John
I had posted that I had read negative reviews of the Eta PackLite. I went back to try to find them. Actually, I was confused. I had mis-remembered which review was which. The negative reviews that I had read were for the Eta Express not the Packlite. The Eta Express was taken to task for a poor windscreen and a piezo ignition that frequently fails. Indeed, I have, and I appreciate it. Very interesting to note the grams (grammes) of fuel wasted in liquid feed mode. I hadn't thought of that. I suppose one could work around that limitation by factoring it into how one uses the stove. Despite the fact that the tests look skewed, I think they demonstrate rather vividly one of the drawbacks of gassies: inconsistent performance as the tank depletes. Supposedly, regulated burners like that on the MSR Reactor that keep the pressure consistently low lend themselves to more consistent results. I haven't conducted benchmark tests, but supposedly liquid feed gas stoves deliver far more consistent results as the canister empties. A liquid feed eliminates fractioning issues and adiabatic and phase change related cooling. Your tests also go to show just how hard it is to compare different stove, pot, and fuel combinations. HJ
Well, first off, boiling tests are a good excuse to fire up stoves. Thank you, John, for more interesting results. I've always liked my Svea 123's more than my 8R/99's. Not knocking an 8R or 99 but I've always felt the 123 was just a bit better. It's got to be that brass windscreen. Fascinating that the 99 with a pump wasn't equal to a 123. I think the 8R/99 design allows for too much air flow. I remember being frustrated in windy conditions on backpacks with dad's old 8R. Interesting that the Primus 210 comes out so well and that the 96's, with one exception do quite well. The "discus" design for a kero stove is a good one. HJ
From what I've read elsewhere, boiling times and fuel consumption are typically inversely related. That is, as boiling time shortens, fuel consumption increases. The faster the boil, the more fuel you'll need. Boiling times can be an indicator of efficiency, but really you have to throw a fuel consumed factor into the equation to really sort things out. Most of what I've read on backpacking sites is that running a stove flat out (maximum output in other words) is not efficient. The typical recommendation I've read is to run the stove at about three-quarters output to get fuel economy while still getting a decent boil time. All this to say, it's REALLY hard to compare stoves. Is alcohol lighter? Gas? Liquid? Which is least expensive? With so many factors, it's hard to know. If the amount of fuel consumed by the Veritas is correct, then I suppose there's one stove I won't be taking on a backpack. HJ
I am a backpacker! But I agree with you. On long trips I'm a bit cavalier on how much fuel I take - I base it on how much I use over a weekend plus factor it one way or another if I feel circumstances dictate. It's pretty easy to do as I only have 2-3 stoves I use regularly backpacking. Car camping - I usually take more than I know I need - I'm a bit too lazy to calculate it too finely.
I agree with both of you. I wish the maker's would stop quoting boiling times as they mislead new stove users. I also have reservations about the heat outputs claimed by the makers. A 2 pint "Primus" stove creates about 2500 - 3000 watts with an impressive flame. Many of the gas stoves claim about the same heat output but with a pathetic flame. Some are even described as powerful when they only have a heat output of 2000 watts Regards Bryan
For me.. If a stove can cook an egg, fry a bit of bacon and make a brew Without breaking my back, then thats okay by me. When out in the wilds i dont take too much heed to time as in seconds and minutes. More so how many clouds drift past in the time it takes to get a mug of tea or coffee in my mitt. Life at work is all about tempo, speed, how swiftly one can carryout a task bla bla. I want to kick that into touch when i am enjoying this planet of ours. (And no ! i'm not on the wacky backy.)
Now, You you would think the guy would be far too busy with playing in band "THE WHO". The guy must have a lot more time and energy that i thought
Not really. But PETE Townsend kept pretty busy with The Who 8) Something else to consider with boil times. It doesn't matter if it takes 3 minutes or 10 minutes to boil, if you use crap tea or coffee just because you're out and about you'll end up with a bad brew irrespective of how long it takes to make Cheers, Graham.
That Graham Is so so true ! So when did Pete take over from his brother Chris in the band ? It must have been all that camping that instigated the " SUBSTITUTE "
