My favorite trail stove is the long defunct Optimus 111B. Known for its power, simplicity and reliability, the B still retains a strong following. One of my favorite B’s is over 50 years old and though it’s been hammered to death on scores of northern trips, it still runs fine. I can’t say the same for some modern “tinker toy” (two-piece) stoves I’ve used. Here’s why:
Modern stoves have a separate fuel tank and armored fuel line. You must connect the line to the tank every time you use the stove—then disconnect it afterwards. This constant connect/disconnect cycle wears the connector and/or O-ring and in time, fuel may leak here. Foreign matter can also become lodged in the valve or connector when the stove is assembled. If this happens, it’s game over—you’d best know how to build a fire! Some years ago, my MSR XGK sprang a leak while running full blast. Gas flamed five feet high! Fortunately, the stove was sitting on a rock near the lake. I kicked it hard and it went sailing into the water, never to be seen again. George Drought, a Canadian paddler of some fame (George invented the “tundra tunnel”, featured in my book, “CANOEING WILD RIVERS, 5th Edition”), had a similar experience on the Back River in Canada’s arctic. He suffered serious burns and had to be air evacuated out.
This said, two-piece stoves are remarkably safe. Those that report problems tend to cook for large groups, which means bigger pots, longer running times and hotter tanks. Still, given equal materials, a one piece stove will be more trouble-free than a two piece stove.
WHY TWO PARTS TO PUT TOGETHER?
The idea of splitting a stove into two parts—burner/fuel line and fuel bottle/pump assembly—began as an advertising gimmick. Let’s say that each of the two parts weigh one pound. The manufacturer can (will!) list only the weight of the stove but not the weight of the tank and pump. Twisted thinking? Yes. But lightweight sells and most buyers won’t have a clue.
The advantage of a two-piece design is that the stove can have a long fuel delivery tube that will keep the tank away from the hot burner. This is a good thing, especially, if you use large pots that reflect heat onto the tank. Ironically, most fuel lines are too short—they don’t allow enough space between the burner and tank—so for safety, you should ALWAYS use the aluminum wind-screen that separates the two. A thin aluminum fuel bottle (tank) is less rugged than the heavy brass and steel tanks of yore. Over-pressurize an aluminum liter bottle and it may blow—which is what happened to George Drought on the Back River.
Some self-contained stoves, like the Optimus 111B, 8R and Phoebus 625 have a mechanical jet-cleaning device. Turn the adjuster knob and a gear-driven needle pokes up through the jet and removes carbon build-up. Compare this to the engineering “marvels” used on modern “tinker toy” stoves:
The “magnetic miracle: A magnet pushes a weighted cleaning needle through the jet. Works great. For awhile. Then, the needle shaft carbons up and the needle begins to stick. If the needle sticks while the stove is running hot, the needle may weld itself to the burner. It’s happened twice to me with two different stoves from the same manufacturer! I removed the needle and now use a manual cleaning tool.
The “shaker jet”: Vigorously shake the stove and a weighted needle slides up and down through the jet. Same problem as above—if the stove carbons up the needle may stick and weld.
Magnetic cleaning devices and shaker jets are handy but they may not have enough power to push a heavily carboned cleaning needle into position. They are fine for casual use, but can be problematic on expeditions where stoves take a beating.
The old brass and steel tanks on Primus and Optimus stoves had a spring-loaded safety valve in the cap. If the tank became over-pressurized by heat, the safety valve would blow. I’ve experienced this several times with my 111B and Primus 71 stoves. It’s not a spectacular show—a thin stream of gas squirts from the safety hole in the cap, that’s all. The remedy is to turn off the stove and allow it to cool. The valve cap will re-set itself in a few minutes. Tinker toy stoves don’t have re-settable safety valves!
Just turn off a one-piece stove, release the pressure, then pack it way. No need to unhook a fuel line (and get gas on your hands) or to fold carbon-black burner supports.
The old self-contained stoves had real windscreens. Modern two-piece stoves have flimsy aluminum-foil deflectors that catch grease and fly well in wind.
The old one-piece stoves were heavier (weight could be reduced with modern materials) than modern two-piece stoves but they were more rugged and reliable. They didn’t have to be assembled, disassembled or cushioned from impact in transit. There was no danger of foreign material getting into an open connector or valve. They had fewer parts and were easier to maintain in the field. Some self-contained models, like the Optimus 111B and 8R came encased inside a hinged, steel box. Just open the box, pull out the burner and you were good to go. What could be easier?