QuietStove.com

Wednesday, February 27, 2013

Canister Gas Stove Reliability & Maintenance

Canister gas stoves are extremely reliable.  Reliable as they are, gas stoves are a mechanical device and do have their problems including:
  • Blocked jets due to either carbon build up or detritus from the canister or fuel line. 
  • Kinked fuel hoses (due to improper storage typically).
  • Stripped threads due to cross threading or long term heavy use.
  • Melted parts due to using something that deflects heat downward somehow (improper use of a windscreen, too large of a pot, a heat diffuser, etc.)
  • Crud in the threads (due to being set base down in the dirt or the like)
  • Hardened "O" rings, gaskets, or seals (don't store canister stoves in your trunk or other hot places for long periods and never store in direct sunlight)
  • General mechnical failures.  I've actually seen a cheap Chinese stove fail at the stove's valve: the valve jammed, and the knob unscrewed itself off the valve shaft. The only way I could fix it was to dissassemble the whole thing. The valve was poorly designed and poorly machined. Not all Chinese stoves are bad, but I personally would stay away from "no name" cheapies.
One trick to keeping your stove in good operating condtion is to store the stove in your pot.  Your pot should protect it and keep crud out of the threads.
Packing your stove in your pot helps protect your stove and keep it clean.
The pot is an 850ml MSR Titan kettle.  The stove is a Kovea Spider (KB-1109).
 With care and proper use, you can avoid most of the problems except the occasional blocked jet. It's so rare on upright gas stoves that most people don't carry any tools to work on such a stove.  There's a little more chance of your jet jamming however if you're using a remote canister stove with the canister upside down (for cold weather). Think about it: You're sucking fuel off the bottom. If there's any rust or crud in the canister, it's going to get sucked right into your jet.
A Kovea Spider (KB-1109) remote canister stove running with the canister inverted.
The pot is an Evernew 1300ml ultralight titanium.
If you want to be prepared to clear a blocked jet, you need to carry a) the tools necessary to disassemble the stove to the point where you could get at the jet and b) a very thin wire that you can use to "prick" the jet (slide the wire through the orifice and physically clear any blockage). Be careful though.  If you use a wire too much or use a wire that's too large, you can alter the soft brass of your jet and ruin your stove.  Some stoves, like the two shown below, simply unscrew; no tools are required.
Dissassembling canister stoves to get at the jet.
An MSR Superfly (left) and a Monatauk Gnat (right).
The jet is the small brass object at the top of the base portion of each stove.
Always dissassemble on a clean surface!
Ad hoc field maintenance:  Once I met some Boy Scouts who had a gas stove that wouldn't work. I disassembled it for them and blew out the jet in the direction opposite that the gas would normally flow. I reassembled the stove, and it worked fine. Moral of the story? Sometimes "mouth power" works works in a pinch. :)  Note:  Some stoves aren't necessarily meant to be disassembled.  Check your instructions. 

The only other form of maintenance (other than keeping the stove generally clean and keeping the threads clear) you might want to do is to use silicon lubricant on your "O" rings as a form of preventative maintenance, but personally I've never felt it necessary.
Always keep the connector on your stove free of debris. 
Silicon lubricant can be employed to help preserve "O"rings like the black one shown above (inside the connector).
Also canisters themselves have their problems. Sometimes the canister's valve doesn't re-seat properly. Rare, but it happens. When it does happen, gas rushes out of the canister in an uncontrolled fashion, sometimes at full volume.  Therefore, NEVER put on or take off a canister by candlelight or near a hot lantern or stove. If you have a valve that doesn't reseat properly when you remove the stove from a canister, just calmly screw the stove back on. The valve on the stove will hold back the gas just fine. Try unscrewing the stove again. Often, simply putting on and taking off the stove again will be enough to reseat the valve properly. If not, just leave the stove on the canister and use the stove's valve to control the gas. Be very careful if you pack a canister with the stove attached. You might want to put duct tape or something over the valve knob to make sure it stays closed.

Always keep the threads on your canister and your stove clean and free of debris.
Lastly, always save (and use!) the cap that came with your canister when it's not in use. Keeping those threads clean is important. Coleman brand canisters don't come with a cap, so I always save a few caps from used canisters just in case I buy a Coleman canister or lose a cap out on the trail.
Always keep the plastic cap on your canister when not in use.
Always keep the threads on your stove clean.  Be careful not to set them down in the dirt.
The pot is a Snow Peak 780ml titanium pot.
I thank you for joining me,

HJ

P.S. Feb 28 2013:
Reader Jim H. reminded me of the burning down of the Gleann Dubh Lighe "bothy" (a bothy is bascially a mountain hut) which was caused by, you guessed it, a canister stove. 

The gutted Gleann Dugh "bothy" (shelter) -- destroyed when a canister was taken off a stove by candlelight and the valve stuck open.
Photo copyright © 2011 by Allan and used under a Creative Commons license.
Apparently someone took their canister off their stove by candlelight, the valve on the canister stuck open, the gas ignited, and within seconds the whole place was ablaze.  The people inside apparently lost all their gear and basically were very lucky to escape unscathed.  Had they been in a tent with only one door in the end of the tent, the results might have been very different.  Canisters are normally very safe, but
NEVER change a canister near an open flame or a heat source.

4 comments:

  1. I had a plugged jet on a Hank Roberts Mini Stove that I had modified for modern canister gas. I wasn't able to blow it out and my biggest problem was that I couldn't see the jet without a magnifier. I carry a pocket magnifier, but have difficulty holding the jet, a cleaning wire and the magnifier. With this type of situation, it's very easy to drop something. It's best to do this sitting down and working over a cloth or tarp that will catch loose parts. I eventually got the jet clean and made a metal filter that fits inside the canister adapter on the stove. I have also experienced the canister leak problem and, as you say, I just screw the canister back on and leave it. I do use silicone lubricant on O-rings regularly, but I probably won't use any on my canister adapter O-rings, because I think that it will just trap dirt.

    ReplyDelete
    Replies
    1. Hi, Bill,

      Good thoughts all. I've had my Hank Roberts type stoves jam too -- several of them (I think I have three). They seem particularly prone to jamming, but it could be how I've rigged them for use with modern canisters.

      Good practical tips on using a cloth or tarp to catch parts and to not use silicon lubricant on exposed "O" rings because the lubricant may pick up debris.

      HJ

      Delete
  2. Here's another case of valve or stove problems and an example of what can go wrong, it's certainly worth being very careful - http://tracksterman.tumblr.com/post/21769003488/gleann-dubh-lighe

    ReplyDelete
    Replies
    1. Jim,

      Thanks for that link. I may incorporate parts of it into my blog post. It's certainly a good cautionary tale.

      HJ

      Delete