Companion forum thread to:

Stoves, Tents and Carbon Monoxide - Deadly or not?
Part 6: Measurements on Liquid Fuel Stoves

Nice work! It's easy now to see why some of my stoves have worked fairly well and others so poorly over the years.

But your comments on the Optimus reminded me of a trip in the late 60's with a Svea stove when, late in the evening in near total darkness, the red-hot flame spreader deformed and suddenly shot into the air. Of course, my natural reaction (I didn't want to LOSE it!) was to stick out my hand and catch it on the way down. I had a nice 3-corner brand in the palm of my hand for weeks.

Edited by EricStechmann on 01/13/2008 19:53:48 MST.

> I just wanted to remind everyone that Sil-Nylon is extremely flammable and burns into a fiery mixture of flame and burning ooze
Two comments.

First of all, you just DON'T prime a liquid fuel stove inside a tent! Seriously!

But I have tested silnylon fabric myself, and I found it far less flammable than PU-coated nylon. It did not burst into a fiery mixture for me - I had to apply flame for a little while to get it to burn in fact. I think it would be best for everyone to conduct their own tests on this matter using any scraps they might have spare. Outside.

Hi Roger,

Another great article in the CO series.

Would it be possible to do a companion series of performance/efficiency tests for all of the stoves mentioned in the CO series. This would help us in making a good choice of stove to suit our uses.

The MSR XGK is called “conversation buster” in my circle of walkers. I experienced this in New Pelion Hut on the Overland Track Tasmania, one walker who was walking with his very pregnant wife and young child kept his XGK going for about an hour cooking lunch we found it very noisy and annoying.

Tony

Hi Tony

> Would it be possible to do a companion series of performance/efficiency tests for all of the stoves mentioned in the CO series.
I don't have any plans to compare ALL the liquid fuel stoves at this stage. To my mind they are all far too heavy for fully paid-up BPL UL party members ... :-)

I do have some plans to do some comparisons between some of the canister stoves in the not-too-distant future (like within the next 3-6 months). After that ... we'll see what can be done.

> The MSR XGK is called “conversation buster” in my circle
It's been like that for the last 20 odd years! Well, ever since the first version was released.

Cheers
Roger

I tried to click on the Part 5 link on top. It doesn't work.

Eins

> I tried to click on the Part 5 link on top. It doesn't work.
Neither did the links to Parts 2, 3, 4. Sigh.
OK, try again: all fixed.
Thanks for spotting this!
Cheers

Edited by rcaffin on 01/11/2008 13:25:49 MST.

Yep, Now it works.

Eins

Roger, well done! I have a couple of the stoves tested in your article - the MSR International and XGK - but seldom use them because of the weight. However, when I forgo an alcohol burner for a gas stove, it's the Brunton Crux that goes with me, a stove that seems popular with many UL hikers, as is the similar Vargo Ti. One feature that caught my attention right away with the crux was how close the pot was to the burner and how wide the flame pattern was, which precluded using small diameter pots like the Snow Peak solo. Anyway, I think the Crux would be a worthy candidate for you to test, given its popularity. Just for grins, I think I'll fiddle with the clearance and see if that improves performance.

Edited by TarasBulba on 01/18/2008 12:11:41 MST.

Hi Monty

What you call the Brunton Crux is actually the Optimus Crux. For a while there was a link between the two companies and Brunton marketed the stove as the 'Brunton Optimus Crux'. it is now just the Optimus Crux, and this was included in Part 3 with other canister stoves.

It emitted far too much CO at the factory clearance, but improved with an extra 10 mm. The heating rate was not very high at either clearance.

cheers

Is it possible to make a pot, rather like teh bottom of a canister and concave, that would reduce CO emissions from having a smaller area of contact at the CO producing small distances? The curve could be slight to still allow most of the heat absorption, but would probably a pain to clean

Hi Jonathan

> The curve could be slight to still allow most of the heat absorption, but would probably a pain to clean
Hum ... not sure what effect it would have. I admit to reservations.
Making it would be a hassle; cleaning it would be worse!

Hum ...

Would a pot like this raise the center of the pot enough to reduce the CO, yet retain any heat lost by doing so?

Price and weight wise this might be better than a separate (msr) heat exchanger, and might work better as well.

interesting idea in using it to raise the center.... I can't find the pic... but I've seen one of the bottom and the there is a ring under the heat exchanger that would allow the stove legs to not fall inside of the heat exchanger...

> Would a pot like this raise the center of the pot enough to reduce the CO, yet retain any heat lost by doing so?

Don't know ... YET.

Hi,

There appears to be a glitch. The part 6 article ends on the what appears to be the first page - the CO table.

It has been like this since I first tried to access the article two days ago (2009-Feb -01.

Hi Robert

Thanks. I don't know what has happened, but it WILL be fixed!

Cheers

"Note that while it is possible to use unleaded petrol or auto gas in such a stove, it is very unhealthy and we recommend strongly against doing so."

What is the problem with unleaded? The only time I willingly use my whisperlite is when I go somewhere like Africa, where to my knowledge the only fuel readily available is unleaded. It is usually no problem cooking well away from the tent, in the open, in these circumstances. Is that enough precaution?

Hi Roger,

Yes it is fixed now.

Note for Derek re unleaded petrol....it will, if used a lot, clog up the jet. In Scotland I use Aspen4T, which is a fraction of the cost of Coleman fuel (approx £15/5 litres against £6/500ml for Coleman fuel. Aspen 4T is virtually odourless and is essentially the same as Coleman Fuel/ Naptha. Optimus recommend the alkylate petrols for their petrol stoves.

Aspen fuel see:http://www.aaoil.co.uk/environment-Aspen-4T-alkylate-petrol

Hi Derek

> What is the problem with unleaded?
First some history. Before petrol (auto gas) was unleaded, the tetra-ethyl anti-knock additive lead in the fuel used to leave the lead at the jet, blocking it up over time. What lead got out could be inhaled, which is even worse.

Now lead has been removed, making car exhausts a little safer. But they have put other things in the fuel to compensate, and some of these are quite unhealthy for us too. In addition, auto gas usually contains benzene, which is a well-known carcinogen.

Coleman Fuel and Shellite have been formulated to avoid all (well, most) of the nasties, so they can be safely used as a stove fuel. I have not met Aspen 4T before, so I know nothing about it, but the company web site makes it sound much cleaner as well.

> It is usually no problem cooking well away from the tent, in the open,
Most likely this is OK to do when you have no alternatives, as long as you make sure you are not breathing in the fumes from the cooking or the fuel. One good way to handle this is having the stove up on a table outside so your head is not above it. Obviously, cooking inside a tent would be a bad idea with unleaded.

Hth
Cheers

Edited by rcaffin on 02/03/2009 13:20:29 MST.

These comments are intended for Roger Caffin and are meant to be constructive rather than critical.

First I must say that although first taking a quick look at these series of articles a few weeks ago I am only now starting to read them as I spend as little time as possible anywhere near a computer! – and I just happened to look at Article No 6 first!

I use Kerosene stoves and WG stoves almost every day, and as such I would like to make some comments on priming.
Roger writes “However, with the most care in the world, priming a liquid fuel stove usually results in a fireball of some size”.

The priming of a liquid fuel stove should never result in a fireball of any size. I never get a fireball with any of the numerous liquid fuel stoves that I use.
With Kerosene stoves priming with methylated spirits only is all one needs. There is no need to “allow some kerosene to mix with it “(methylated spirits).

Some priming cups on some stoves are of poor design and do not hold sufficient methylated spirits to vaporise the paraffin. When this is the case and if the stove user opens the control valve too soon and then lights the “vapour” a large flame can result due to the incomplete vaporisation.
If one double primes – that is burn the meths in the priming cup and as soon as all the meths has been burt immediately refill the priming cup with meths and re-light. When the second prime is almost complete open the valve and the stove should light. If not immediately light the stove with a lighter. This is the method I use almost every day and I get immediate burner ignition and no soot.

I use the same method when using WG (although in the UK I use Aspen 4T [http://www.aaoil.co.uk/environment-Aspen-4T-alkylate-petrol] as it is less than a quarter of the price of Coleman Fuel.)

Some comments on the Optimus 8R. I am very familiar with this stove as I have several Optimus 8R’s of various vintages and a Russian military 8R copy.
Roger’s method of priming the 8R “Typically, you prime this stove by removing the fuel cap and blowing, hard, into the tank until fuel dribbles out at the burner. The big brother to this stove actually had a pressure pump, which saved you the taste of fuel.” Must be unique to Roger and is not to be recommended.

The Optimus 8R and its copies are very easy to prime: Fill the priming cup with methylated spirits, light and when the flame is almost extinguished open the valve. The stove should light immediately. In cold weather double priming as described earlier will ensure the stove will light. In very cold weather one can use the optional midi/mini pump.

In 1976 Optimus introduced this accessory for self pressurising stoves (Optimus 8R, 99, 80 and 123). The pump consists of a special, elongated pressure relief fuel cap and a small detachable, external pump to fit over it. Pressure is built up in the fuel tank by forcing air through the pressure relief cap. This pump is still available: In the U.K. from Base Camp: http://www.base-camp.co.uk/ and in the U.S.A. from A&H Enterprises in California: http://www.packstoves.com/cart/

There were at least three clones of the 8R. The Taiwanese copies are an Appolo and a Trail-Pak stove. The South Korean firm of Shinabro also copied it and sold it as a 170GR but rebadged it as a Precise Phoenix Backpacker which is an American brand name. The Trail -Pak stove is distributed by a Canadian company so it may be a rebadged Appolo.

With regard to Roger’s adventures in his tent with the 8R , and the unnamed BPL staff member with his SVEA 123 I would merely comment that when using small backpacking stoves one should use small pots/fry pans – sometimes it is not a faulty stove – just a lack of common sense on behalf of the user!

Roger says: “I have to add that kerosene stinks a lot more than WG!” I admit a bias here, being a kerophile rather than a kerophobe – but I personally don’t think good quality kerosene stinks at all – in fact I like the aroma of kero! Then, as someone who thinks that life is too short to drink bad whisky, my nightly dram of 25 year old Caol Ila’s “nose” would probably stink to those who don’t like west coast (West coast of Scotland) malts!

Recently in my part of Scotland we have enjoyed a lot of snow and temperatures down to -20C. I used my 1950’s Sievert Svea 123 running Aspen 4T at -13C in snow and by using good priming technique and having a small cut-off from an old kip mat the stove, insulated from the cold ground lit successfully every time (no fireball and instant ignition). At the lower temperature near -20C I used a 1930’s Optimus kerosene stove with equal success, no flames, no soot, just instant ignition after proper priming.

Sadly, every year in the field, I observe people using liquid fuel stoves incorrectly – none seem to realise that the flames enveloping their modern multi-fuel stoves whist attempting to prime is anything other than normal. It is sad because if they knew how to prime correctly they would have clean stoves, clean pans and enjoy their cooking and brews just a little bit more.

When time permits I look forward to carefully reading all the articles in the series in which Roger obviously put a terrific amount of hard work and enthusiasm.

Just to reiterate, my comments are meant to be constructive – I would like to see people use liquid fuel stoves safely and successfully.

Best wishes,

Robert

Hi Robert

Thanks for the time you have put into your posting. I learnt much from it.

> The priming of a liquid fuel stove should never result in a fireball of any size
Oh, I agree. I could always light my Coleman Peak Apex and my Whisperlite when burning kero (with metho priming of course) without a fireball. A clean ignition was a matter of pride.
What I meant was that so many people seem to habitually create a fireball that it 'seems' almost inevitable. And then of course we have the direct quote from the MSR XGK instructions:
> 1. Release only 1/2 tablespoon of fuel
> 2. Light fuel
> A brief soccer ball size flame is normal.

> “allow some kerosene to mix with it “
OK, I understand the question here. I found that priming a kero stove worked best if I allowed the preheat/generator tube to fill with kero before priming. As the kero in the tube got hot it would start to leak out the jet, mixing with the metho. This worked very well for me.

> Roger’s method of priming the 8R ... Must be unique to Roger and is not to be recommended.
It was certainly not unique to me! Many of my friends did it this way. It is possible to get some priming fuel out of the tank by opening the valve and warming the tank with your hands - but that was slow and many were too impatient. So, they blew. And fireballed.

You know, I never thought of priming an 8R with metho. Of course it would work! Very smart - in hindsight.

> There were at least three clones of the 8R.
Really? I did not know there were so many. The designer of the 8R must have been gratified by the number of clones, even he was if short on royalties. I will see if I can find mine and identify it form what you have said.

> The pump consists of a special, elongated pressure relief fuel cap and a small detachable,
> external pump to fit over it.
We knew about this pump being available for the big brother kero version of the 8R, but as far as I can remember the pump for the 8R was never imported into Australia. I didn't even know one existed. No internet/web in those days, and we only saw what the importer selected.

> (wide pans) ... just a lack of common sense on behalf of the user!
Well, yes and no. Bear in mind that this was in the early 60s, and we were very young. I would not say it was "common" sense in those days: we simply had very little experience to draw upon.
"Wisdom comes from experience; experience comes from a lack of wisdom."
In fact, in those days just having a stove was kinda new - most used a fire.

> I personally don’t think good quality kerosene stinks at all
I suspect that will depend very much on the refinery and the shipment of crude oil used. In the 60s our kero stoves all smelt, and even in the 80s here in Australia kero always made some head-clogging fumes. And in Nepal too I might add. OK, I didn't mind the smell too much, but I was near the open tent door. My wife, at the back end of the tent, lacked access to fresh air! Anyhow, gas is so much more convenient.
But now I think about it, I do remember that the kero room heater we had in London when I was doing my PhD there did not smell very much. Hum ...

The Aspen 4T fuel sounds like a good brew. Not available in Australia of course. Our Shellite is not bad.

Cheers
Roger