MSR Reactor in Cold Weather

I've taken my MSR Reactor in some colder trips at an elevation of between 10k and 14k here in Colorado, and the performance has been pretty bad. I'm using MSR's winter mix canisters, keeping the fuel warmish under my clothes/in my sleeping for hours before using it, but the fuel still sputters out and the flame is weak. I thought this stove is used on Denali?

Any tips to have a better experience? I do see there's a remote stove adapter, but it doesn't seem like it's made to also invert the canister, 

https://www.msrgear.com/stoves/stove-accessories/lowdown-remote-stove-adapter/11582.html

Some ideas I was going to experiment with were to create a canister coozy to both store and use the canister with, using insulated padding so the stove isn't on the cold ground. Any other obvious and cheap ideas?

Do you know the water-cup trick?

I use a variation of the design in this post: mountainproject.com/forum/t…

it’s not the ambient temperature that cools the canister (though that is what sets it cold at first), but the expansion of the gas that makes the canister even colder than before! Using liquid water as a thermal sink will keep the gas in usuable range. Save about 400ml of water for your seed water when melting snow, and for the water cup trick. 

Long Ranger wrote:

Any other obvious and cheap ideas?

https://bushcraftusa.com/forum/threads/so-youd-like-to-be-able-to-use-canister-stove-in-the-winter.273430/

Ben Podborski wrote:

Do you know the water-cup trick?

I use a variation of the design in this post: mountainproject.com/forum/t…

it’s not the ambient temperature that cools the canister (though that is what sets it cold at first), but the expansion of the gas that makes the canister even colder than before! Using liquid water as a thermal sink will keep the gas in usuable range. Save about 400ml of water for your seed water when melting snow, and for the water cup trick. 

Water bath trick has been most reliable for me. 

I'll try out the water bath trick this weekend, thanks for the tip, all.

Long Ranger wrote:

I do see there's a remote stove adapter, but it doesn't seem like it's made to also invert the canister, 

MSR has dire warnings about trying to use WindBurner and Reactor stoves with an inverted canister.

Can I run the canister inverted with my WindBurner® Stove?

No, the WindBurner is not designed to be used this way. To achieve similar performance to an inverted canister in cold weather and with low fuel, the WindBurner uses a built-in pressure regulator. This regulator design allows the stove to deliver a faster and more consistent cooking experience than using the canister inverted, down to 32°F/0°C canister temp.

Do not invert the canister on your WindBurner stove. Doing so can lead to extremely dangerous flare-ups or liquid fuel build-up. If you wish to use the WindBurner in temperatures below freezing, place the canister in a bowl of water. As long as the canister stays above freezing, it will operate at full output, providing fast boil times and excellent fuel efficiency.

I think the reference to 32°F is quite conservative. At 10,000' isobutane fuel should be fine down to roughly 15°F (at that elevation its boiling point is about -5°F). Blended isobutane/propane fuel can be even colder. Just bear in mind that the canister can get colder than the surrounding air as the gas inside vaporizes, as Ben points out above.

Noted about not inverting.

I think the reference to 32°F is quite conservative. At 10,000' isobutane fuel should be fine down to roughly 15°F (at that elevation its boiling point is about -5°F). Blended isobutane/propane fuel can be even colder. Just bear in mind that the canister can get colder than the surrounding air as the gas inside vaporizes, as Ben points out above.

That's the thing - I've never used the Rector down to 15F, and it's performance has been lack luster at temps more near freezing. 

Works fine back home on my deck. 

I'll try the water bowl trick. Not sure if I can route a piece of copper from the flame to the canister, as the stove and built-in windscreen is pretty integrated, but I'll look at it more closely soon. Lows shouldn't be anything below freezing this weekend. 

Does the stove sputter right after you get it running, or does it run great and then slowly get worse as the canister cools off?  Does warming the canister up with your hands or water make the problem better?  If it's not running well with a warm can right out of the gate, it's not the can getting cold, and a water bath or whatever isn't going to help.  More details about the behavior would make it easier to troubleshoot.

Borrow another Reactor from a friend/local and try it out in the same conditions, or see if MSR will look at your stove.  I've used Reactors and Windburners in Alaska and they have always worked great, it shouldn't be an issue.  You might have a problem with your stove, it would be really beneficial to rule that out first, before you do more complicated troubleshooting.

My partners and I used a Reactor and a Windburner on Denali and they were both fine up to 18k, no water bath or other trickery besides a warm can and maybe dumping a bit of water on occasionally.

Kyle Tarry wrote:

Does the stove sputter right after you get it running, or does it run great and then slowly get worse as the canister cools off? 

You know how when you turn on the gas and you light this sucker up - it's like you gotta mini jet engine sitting right there, ready to singe your g/d eyebrows off?

It never even gets close to that. I may get some sort of ghoulishly weak blue flame, but it never really takes off. If I"m lucky, it feels like it's at a quarter of its true power - like only part of stove is really lit. 

This is out of the gate and this could be after warming the canister up for a few hours underneath my coat. The last time I tried, I had two different canisters, and they both had this problem when I swapped them out. 

Anything I should look for on the stove itself? I wasn't aware that there is any maintenance needed for the stove Some build-up somewhere?

I've used this stove in summer time at 12k/3k without a problem. It's been pretty babied as far as stoves go when not in use.

Yeah, if it’s not firing up right away with a warm can, all this talk of canister warming and baths isn’t going to help.

Are you lighting it via the special Reactor light spot, at the edge above the logo?  I’ve seen these sputter and act weird when you just light them haphazardly.

I don’t know anything specific about maintenance, just saying that testing another one would confirm if yours isn’t working right in the same conditions.

Jimmy Strange wrote:

Check the ‘safety’ cut out hasn’t been flipped. Sounds a bit like when that happens. Just gurgles away with a spotty burn that can even be blown out. 

Where is that located? 

Reading the instruction manual, " If stove is misused the device will be
de-activated and render the stove permanently inoperable" 

Cool, cool.

https://www.mountainproject.com/forum/topic/114547789/msr-reactor-stove-troubleshooting

" Next to the red switch, where you turn the fuel on and off, there are diagonal metal slits (all the rest are just circles.) They are located right next to the + and - signs. Turn the fuel on, light the stove, and then cover these with your thumbs.  Those are part of the air intake and covering them acts like a "choke" feature. In a couple of seconds the stove should glow red."

"A well known issue. Reactor is equipped with kinda safety-lock. It is a bit of lead melting when overheated so it leaks into gas providing channel and corks it. To fix it all you need is a piece of 0.010" guitar string. Disassemble your Reactor, remove all lead from gas pipe and enjoy your ready-to-blow Reactor. After this modification your Reactor will have no protection against overheating."

OP said their stove works fine in summertime, so it's probably not the thermal fuse, right?  If the fuse was popped I think it would work like crap all the time?

OP, if you fire the stove up right now in your kitchen, does it work?

Fired it up today at home - no problem, so I doubt I triggered the fail safe thing. Tested out the "choke" too - that seemed to make a big difference. Forecast for the weekend has changed to be much colder - down to the low 20's at night, so we'll see if I get hosed or not camping at 12,000'. Should still be some running water around my campsites, so this is more of a dry run before far more serious trips in the future.

There was heat shunt described in the link that I posted earlier in the thread. You still have time to play with it before your trip

We'll see if I do have time - I leave tomorrow (hopefully). Here's the idea applied to the Reactor from the BLP thread that goes on for like 20 pages, 

I'll chime in to say that I've also never had any luck with any gas stoves at altitude or cold.  I have always been puzzled when I've seen them used in Alpine situations, as my experience is that I need a liquid fuel stove to feel confident I'll be able to melt snow.  In summer I use them a lot and love their performance.

Climbing the Cassin Ridge some years ago, my partner & I had a big discussion about it and ended up bringing an XGK because we just couldn't feel confident in gas stoves.  I wish it were otherwise, because the weight, size, and speed of canisters is very appealing.  I remain a bit confused after reading this thread!

evan freeman wrote:

I'll chime in to say that I've also never had any luck with any gas stoves at altitude or cold.  I have always been puzzled when I've seen them used in Alpine situations, as my experience is that I need a liquid fuel stove to feel confident I'll be able to melt snow.  In summer I use them a lot and love their performance.

Climbing the Cassin Ridge some years ago, my partner & I had a big discussion about it and ended up bringing an XGK because we just couldn't feel confident in gas stoves.  I wish it were otherwise, because the weight, size, and speed of canisters is very appealing.  I remain a bit confused after reading this thread!

Kyle Tarry and I used a MSR Windburner on the Cassin Ridge and it worked flawlessly. 10/10 would windburn again. Keep your stove canisters in your sleeping bag overnight.

Got out and used the Reactor at 11,500'/20F and it worked just fine. Stored it in my sleeping bag for the night, used the water bowl technique and the choke to good effect. Fuel was some old 100g Jetboil canister I've had forever. The canister did eventually freeze the water in the bowl and stick to itself after about 40 oz brewed, which made a small job of chipping that ice off. I used a waterproof stuff sack turned inside out, put the canister in there and put that all in my chest pocket for a few minutes to melt everything before stowing. 

 So I guess I'm happier. Funny that the larger, newer, MSR canister didn't work as well last spring. I'll play with that copper strip as soon as I source some freeish copper. 

Thanks for the report! You can also top-up the water cup with heated water from the boiler!

We had our MSR Reactor fail on us at 19k on an expedition we just got back from. The way you describe the fuel sputtering is also what we experienced at first, but it gradually got worse and worse until there was no fuel coming through the top of the stove at all (with an almost full canister attached). Turns out it was the safety lock mechanism with the melting lead block in the fuel lines.

We took our MSR windburner up next time on the route and it worked fine at 19k. Oddly enough a weld on the pot failed and made it wonky to use but at least the burner worked. The windburner had a re-settable overheating safety lock function so in theory should never have those problems.

Anyways, I’m kinda un-sold on the Reactor. Can’t be having critical stoves failing like that randomly.