Sunday, 22 August 2010

MSR Reactor in Use

As you'll know if you read the wildcamp report I managed to take the Reactor into the hills for a test. Much of what I've already mentioned re the MSR Reactor is repeated here for clarity together with some additional information so bear with me.

I decided to take a part used 100g cartridge, the one I’d been using to test both the Reactor and the Fly (ti) at home. Unfortunately as it was all a bit rushed I forgot to take my video camera, forgot to take my thermometer and also forgot to weigh the gas cartridge before I left. As I know the cartridge weight after the last recorded test at home I’ll have to assume that it was the still the same when I packed it for the wild camp (I’m pretty sure I didn’t use it after the last recorded test) For what it’s worth it weighed 158g after the final Fly (ti) test.

My usual meths burner set-up weighs 178g and with 100ml of fuel the total weight would be 278g, the MSR Reactor weighs 486g as weighed by myself, added to this was a plastic mug, large plastic spoon and pouch cozy at an additional 113g. I also took a Primus’Footrest‘ to improve stability as I was using the 100g cartridge, this added a further 24g and finally the gas cartridge at 158g brought the total weight up to 781g, almost 3 times the weight of my normal set-up. It has to be remembered that I would expect to boil in excess of 4l of water with the 58g of gas remaining while the 100ml of meths would most likely only boil 2l. Unfortunately that’s a fact of life if you choose gas, you can’t simply take the fuel you require and even if you could choose from a selection of part used canisters you still have around 90g simply due to the weight of the cartridge itself. Although the MSR is large enough to carry a 220g cartridge it isn’t significantly larger than my meths set-up due to the way I carry my beer can pot in a closed cell foam cozy so it easily fitted into my pack (ULA Conduit) horizontally still leaving space at either side and in front.

As it turned out I wasn’t the only one to forget something, Marcus who was accompanying me realised he’d forgotten to bring fuel for his meths stove when we were on route to our proposed camp. While I knew there was enough gas for 2 Marcus has intended to cook sausages and this threw up another issue, you can’t use a regular pot/pan with the Reactor in an emergency in the same way you could with the Primus Eta Express or buy an additional pot support like you can for the Jetboil PCS.

When we finally reached our camp site it was about 7.00pm, and while the conditions were perfect for a wild camp, unfortunately they were also perfect for mountain midges, the Northern Irish variety being no less voracious than their infamous Scottish cousins. What should have been a leisurely evening meal turned into something of a trial by midge and the speed and ease of set-up of the Reactor was very welcome indeed.

I didn’t attempt to record the time taken to boil water as I wear an analogue watch ( I realised afterwards that I could have used my mobile phone!!) but we initially boiled about 1.0l followed by an additional 300ml or so, I can’t say exactly how much but I used all the water in my flexible bottle/bladder plus the contents of my Aquagear filter bottle, total about 1.8l although I did use some to cool my coffee.

Having been used to setting up my meths stove before preparing my meals it felt strange to have everything set-up prior to lighting the stove. The stove boils water so rapidly that you simply don’t have time to mess around, at one point I was taking some photos while the stove was in operation and almost forgot to check on it. It would be easy to waste gas if you aren’t careful as the stove will burn happily until the cartridge is empty. That isn't really a criticism and wouldn't be an issue for those used to gas stoves but when you’re used to metering out exact quantities of meths it’s easy to forget.

The stove was used again in the morning, fortunately there was enough breeze to keep the midges grounded, again 1.0l was boiled which provided us both with hot drinks and in my case Muesli.

We had intended to stop a few times on the 2nd part of the route but the constant attention from midges while on the hill kept us moving. We did however manage a lunch stop on the final summit of the day where again approx 1.0l was boiled, sufficient for 2 cups of soup and 1 coffee.

As I mentioned at the start I can only provide an estimate of water boiled/fuel used, the cartridge was weighed once we got back and was 125g. I’ll estimate that we boiled between 3.0l and 3.5l and used 33g of gas which works out at approximately 9-11g of gas used per 1.0l of water boiled which is fairly consistent with the results I had on the recorded tests at home, slightly better in fact although I suspect that it’s more efficient to boil 1.0l once rather than 500ml twice.

In conclusion I have to say that I was very impressed with the stove, on performance/efficiency alone it outperforms any gas stove I’ve ever tried including the Jetboil PCS which is a similar type of stove. I also feel it surpasses the Jetboil in that for no increase in weight it has a greater capacity as the pot easily holds 1.5l and still has about 15mm to spare while the Jetboil can only manage around 500ml if you fill to the recommended level and has a maximum capacity of 1.0l filled right to the top if I remember correctly. This combined with the ability to carry a 220g cartridge makes the MSR more suitable for duo use. The downside with the MSR is that it can’t really be used with standard pot while the Jetboil can, not being able to clip burner and pot together also means it’s easier to use the Jetboil as a hanging stove. In the end though for anyone considering buying a ‘System’ stove I’d fully recommend the MSR Reactor, it does exactly what MSR claim which in my experience is pretty rare.

When compared to a top mounted burner/standard pot and windshield set-up the Reactor seems heavy however as it uses less gas you could probably manage on a 100g cartridge while the basic stove would require a 220g cartridge, depending on the duration of the trip. In so doing the weight difference is reduced as is fuel cost and you still have the ease of use and fast set-up of the Reactor.

Although it isn’t really my type of stove and is heavier than I’d ideally like to carry I would be very tempted and indeed may well purchase one at a later date for winter use. Unfortunately it has to go back to Hendrik but I’d like to thank him once again for the opportunity to test the Reactor and hope that the results and views are useful to someone.


  1. Tests and results like this are always useful.
    Thanks for carrying them out and sharing.

  2. Thanks Alan, could have been better if the results had been measured but there you go.

    By the way, if you look at the water in the flexible bottle, thats unfiltered Antrim Hills peaty water which is pretty dark and came from a running stream.

  3. Seems like you need a checklist so you won't forget anything next time. :-)

  4. Thanks for the post. It is such an important one reading review like this. Sharing your expertise with this is a big help. I might as well purchase another stove for our next hike. It seems very practical to use.