Companion forum thread to:

Heat Exchanger Stove Shootout: Part 2
Upright and Remote Canister Stoves

Great stuff! Loads of very useful info here.

One thing that seems weird is the observed boil time for the Pocket Rocket. You guys observed 10 minutes while MSR claims 3.5 minutes. Obviously there are a slew of factors that affect this but 10 minutes seems curiously long...especially when all the other upright stoves are in the 5-6 minute range.

I have a Pocket Rocket and while I haven't timed the stove, I don't think it takes anywhere near 10min to boil a liter. 5 minutes sounds reasonable. My wife boiled a liter of water using ours this morning and I was supposed to be packing up the tent while she did so. I didn't even have the fly off when the water was boiled and ready for making coffee with.

Perhaps the stove was partially clogged or the stove wasn't screwed to the canister tightly? The rubber seal on the PocketRocket is pretty stiff and it sometimes needs to be torqued on a little harder to get a full seal.

Edit: I just checked the BPL review on the PktRkt and they observed 3min 26 sec for a 1 liter boil with 15.8g of fuel burned. These numbers are radically different from the ones observed here which indicates to me a problem with your PktRkt. The difference seems to great to simply be caused by variation in temperature, elevation, pot choice etc.

Edited by dandydan on 08/19/2009 00:40:30 MDT.

This is fascinating reading. My conclusion is that remotes by and large have larger heads, because their greater stability allows them to be used with larger pots. I think that if one were to measure them with such larger pots both their boil time and their efficiency would be better. In short, uprights are optimized for solo campers where weight is everything, and where small pots are used. Remotes are heavier, and optimized for use by two or three people.
Willem

I second Dan's comment on the Pocket Rocket. Other than my alcy, my PR is my primary stove and have timed it in fall conditions here in the PNW at just a hair over 4 min for a liter to boil.

If we are to compare stove performance for naked and integrated stoves I think their performance in windy conditions will be crucial. We all know that stoves´ performance deteriorates enormously once there is some real wind. That is why I am so attached to my big Trangia´s. In my part of the world there is almost always quite a bit of wind.

Hey all! Just realized that you guys probably didn't know that Roger was out tramping in Europe this month. Once he's back, I'm sure he'll address your concerns with the Pocket Rocket (and anything else) in the forums, possibly tweaking the article text as well, if there's an error.

Thanks!
Addie

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Edited by truls.cronberg on 07/16/2010 04:12:22 MDT.

Hi Dan

> You guys observed 10 minutes while MSR claims 3.5 minutes.
Point taken. I will have to check this out.
Mind you, the PR still has bendy pot supports and a focused flame which can burn ... My biases are showing :-)

cheers

Hi Willem

> uprights are optimized for solo campers where weight is everything, and where small
> pots are used. Remotes are heavier, and optimized for use by two or three people.

An interesting point, although this applies only in the summer, not in the snow.
On the other hand, I would have no hesitation using my Snow Peak GST100 for a large group: it has the same power as the large remotes.

The interaction with pot sizes - could be.

Cheers

Hi Willem

> We all know that stoves´ performance deteriorates enormously once there is some real wind.

Well, only if you take no precautions over the wind. I have used my stoves in howling gales (100kph snow storms), but inside a tent and with a close windscreen. See When Things Go Wrong".

Quite frankly, if you use your stove without a windscreen you are shooting yourself in the back. It can be futile.

Cheers

Hi all

Yep, as Addie said.
We got back from 6 weeks in the Swiss Alps late last night. The weather was wonderful!
My body is now at home; the brain should follow in a day or two...

Cheers

Hi Roger and Dan,

> You guys observed 10 minutes while MSR claims 3.5 minutes.
Point taken. I will have to check this out.

I have worn out my first PR testing it and my typical results are 5-6 minutes for a fast boil using around 15 grams of fuel to raise water 80C. Slowing down to 12 minutes reduces the fuel usage to around 12 grams.

I do not know where MSR got there 3.5 minutes from, I have never achieve this result.

The PR's aluminum thread where it screws onto the canister is still OK after hundreds of uses, it was the needle valve tip that wore which made the PR not suitable for testing purposes, it is still OK for field use and while I agree that the pot supports are not that good I have never had one collapse or the pot fall off.

Tony

> You guys observed 10 minutes while MSR claims 3.5 minutes.
> Point taken. I will have to check this out.

I have looked through the details test results to see why the PR took so long to boil even at 'high power'. My notes indicate that the stove could run hotter, but opening the valve any more than I did meant the flame was starting to lift off the burner face. having the flame lifting off is a dangerous operating condition as it makes it easy for wind to blow the flame out.

It is possible that running on a different gas mix MIGHT allow greater power: I was using a very common Primus fuel mix of butane, propane and iso-butane.

It is possible that the jet is too small (manufacturing defect) or partly blocked (user problem). However, I have not had any jet blockages with any other stoves during all the testing. But I will check.

If MSR were willing to run the stove on a very high propane mix with the flame lifting off - in a proper test chamber for instance, then they could maybe get a sub-4 minute boil time. However, I have found too many cases where the vendor-quoted boil times are simply fairyland. I don't pay much attention to them these days.

Cheers

Interesting work in progress. Makes me curious to the final results.
Foudn it interesting that the Soto stove was mentioned. I hope the seperate review of this stove doesn't take too long becaue that regulator has gotten my attention. Sounds to good to be true if it weren't for the video's that seem to support their claim. A bit hard to judge though without details of the test set up.

off-topic
@Roger
Where in Switzerland have you been? Did spend my last two vacations overthere so curious to hear your experience.

I own both the VArgo Jet-Ti and the Brunton Flex (like the Primus Crux & made by primus).

The high CO2 emissions of the Crux would surely be similar in the Flex. Holy Cow! What a difference between the Crux and the Jet-Ti.

Guess I'll take the Jet-Ti when I forsee any vestibule cooking due to rainy weather. It's just that the Flex's wider bruner ring gives a much more even heat when cooking and that's why I bought it. Howwever, to get the Flex's floppy pot stands to stay in place I'v had to drill out the rivets and replace them with tiny stainless nuts & bolts and lock washers.

Eric

Hi Tom

SOTO: interesting idea to put a pressure regulator into the gas line, but ...

* It does not boost the pressure in any way at all, despite some ridiculous marketing hype from some retailers. Chalk that one down to pure ignorance on their part.

* The claimed advantage of a constant flame height does not offer any benefit in the field in practice - why should it? I vary my flame height anyhow while cooking.

* The CO emission is worsened by the presence of the pressure regulator for technical reasons.

Well-made stove, interesting regulator control, but ...

Switzerland: Chamonix to Zermatt, then the Alpine Pass Route or Via Alpina from Sargans to Gsteig, then own cross-country route to PlanPraz above Chamonix, then GR5 and Balcon du Leman and cross-country to Thonon. ~6 weeks.
Bewares:
Europaweg trail to Zermatt: active avalanches bombing it and impassible (wiped off the mountain) in one place. Risk to life. We aborted.
Route 82 from Col de Sanetsch down to Godey: Poteau des Etales section: rather dangerous when dry, extremely so when wet.

Cheers

Hi Eric

CO, not CO2 :-)

I could not agree more about taking the Jet-Ti instead. I don't find the spread of heat to be that bad myself.

Cheers

Hey Roger,

Are you still planning to do Part 4 of this series? - am interested to know how pot diameter affects overall efficiency. Thanks, Steve

Hi Stephen

Yes, Part 4 on pot diameter will happen. I promise. It's just that since coming back I have been extremely busy with several other things. I expect to be able to get to work on it within a few months. You know how it is.

Cheers

Thanks Roger - I look forward to that.