MSR Pocket Rocket – Thread problem

Christine wrote above, "The problem was not apparent at first: I screwed the stove onto a brand new full canister and it worked badly, but it still worked".

I strongly suspect that was the mistake from the get go. Different manufacturers make different thread configurations — and forcing one type onto another is just about the quickest way to wear out the threads — and causing permanent leakage. Curious, what was the brand of the fuel canister you purchased in Europe?

But even if the fuel canister was a comparable brand or even the exact same brand, perhaps that particular canister was a dud (it can happen)… and again, force-fitting is a recipe for permanent damage. Stove and canister should fit perfectly and easily — and if not, then something is definitely wrong.

Reading your post tells us that we should always test newly-purchased canisters prior to our trips (I haven't done this but I will going forward). This will help prevent a field situation where we have to decide between force fitting a dud canister (and risking permanent damage to our stoves) — or skipping hot dinners every night!

Addendum:

Christine, your English is excellent! :)

Christine,

Benjamin's right: your English is almost perfect!

ONe of my stoves is the Pocket Rocket and I've never had this problem. Other users I know haven't, either.

If you like the stove, don't hesitate to buy another and always be carefule w/the threads. Sorry to hear MSR won't help you.

Todd

>we should always test newly-purchased canisters prior to our trips

I'm thinking that other than a shake and a good look at the threads, it's probably not neccesary to break the seal. If you do, it's a good idea to use a couple drops of dishwashing liquid in a little water to bubble test the seal for leaks. If you see bubbles, put your stove back on and try a second time. A little spot of dirt on your stove's quill is all it takes to create a slow leak. Once tapped, there's no guarantee the canister will totally reseal, although they usually do. You may pack and find out two weeks later your fuel has slowly leaked off.

YMMV

Dear Christine,
The problem with your Pocket Rocket might also be caused bij the different threads on the gas canisters. As far as I know the Rocket Pocket is only suitable for MSR and Primus canisters, but not for the European Camping Gaz canisters.There seems to be a part (sorry don't know the English name) from Markill to fit on the Camping Gaz canisters and then you should be able to use your Pocket Rocket. I haven't tried it out, though.
Hope this helps.Marianne van Ginhoven

As I have written before I had problems with a MSR pocket rocket but thought that it might be either an user fault or just bad luck so I bought another pocket rocket for my CDT thruhike this year.

Unfortunately, after 3 months on the trail (= about 200 uses of the stove) the same problem appeared and rendered the stove more or less useless. And at that point I was in the middle of nowhere with absolutely miserable weather and a non-functioning stove. I had a real problem!

With the same problem happening twice on two different MSR pocket rocket stoves I do not believe any more that it was a handling problem or just bad luck. I think that MSR is just delivering bad quality. I was never that disappointed with a piece of equipment before.

I therefore recommend getting a different stove if you are planning on using it a lot and depend on it. Hope this warning helps.

Christine

Hi Christine

> As I have written before I had problems with a MSR pocket rocket but thought that it might be either an user fault or just bad luck so I bought another pocket rocket for my CDT thruhike this year.
> Unfortunately, after 3 months on the trail (= about 200 uses of the stove) the same problem appeared and rendered the stove more or less useless. And at that point I was in the middle of nowhere with absolutely miserable weather and a non-functioning stove. I had a real problem!

Yes, this is a known problem, but it is not widely known. It applies to ALL screw-thread stoves. The problem is as follows.

The thread on the canister is roll-formed in very thin metal. It is NOT a complete thread by any means. (Pretty crude in some ways, actually.) This means that a high load is placed on a small part of the thread (the tip of the thread) on the stove. Since the thread on the canister is steel and the thread on the stove is brass (any stove), it is the brass which wears away. Eventually the thread stops holding and you can't get gas out of the canister.

Let me make several points here.

1) This problem applies to ALL screw-thread canisters and ALL screw-thread stoves.

2) You can minimise the problem by keeping the thread very clean and by not screwing the stove down hard. Screw it down lightly and see if the stove runs. If so, that is enough pressure. If not, do the thread up a little bit more. I think this may be where you are having a problem: you are using too much force every time. Be more gentle.

3) ALL screw-thread canisters have the same thread. ALL screw-thread canisters will mate with ALL screw-thread stoves – despite the manufacturer warnings you get with some stoves to 'only use OUR brand of canister or terrible things will happen'. This cross-compatibility is required by law.

4) Despite point 3), you may find slight differences between staoves and canisters which mean the different combinations have to be tightened different amounts. Yes, this happens. But they will inter-operate.

> With the same problem happening twice on two different MSR pocket rocket stoves I do not believe any more that it was a handling problem or just bad luck. I think that MSR is just delivering bad quality. I was never that disappointed with a piece of equipment before.
No, you are blaming MSR wrongly here. I agree that the pot supports on the Pocket Rocket are far too weak, but the thread is the same as every other stove. I think you have screwed the stove up too tight every time, and increased the wear on the threads.

The French Campingaz company did not like the screw-thread when it was developed by the UK firm Epigas, and developed their own system using a different fitting. It is a more reliable system, but seems to be mainly available just in France. The stoves are rather heavy – which is a pity.

Cheers
Roger Caffin
Senior Editor for Technology
BPL

Hi Roger,

thanks a lot for your detailled answer – it really has helped me a lot to understand the problem.

After my problem with the first stove I handled the second one really carefully in order to avoid the problems you mentioned. Apparently it didn't help much… Maybe gas cannister stoves are not meant for long term use.

I have now bought a Snowpeak Titanium stove hoping that titanium is harder and therefore the problem will not appear again. You are writing now that all screw-thread stoves have a brass thread – does that also include the Snowpeak Titanium?

Greetings from Germany,

Christine

Hi Christine,

I would have to agree with what Roger has written except for one thing “the thread on the stove is brass (any stove)” The internal thread on a pocket Rocket stove where the canister threads screws into is Aluminium.

I have successfully used a Pocket Rocket for many years including doing hundreds of lab tests with it and I have never had a problem with threads.

The pot supports are a bit weak but I have never had one bend. The only problem that I have had with the Pocket Rocket is that the brass needle valve has worn a little bit on the tapered surface making flame adjustment a little bit uneven in one part of the range.

One thing that I would caution about and that is leaving the stove screwed on to a canister between uses, I have run tests by leaving a canister attached to my stoves overnight and for several days they all showed some leakage, which does not happen if the stove is not attached.

Tony