It may be too early for me to post this but the problem may be serious enough that I thought I should. My supply of Powermax cartridges are starting to develop leaks after one time use and disconnection while partially full. These cartridges have been out of production for years so any cartridges I have and probably others have are getting old. Your experience MAY BE DIFFERENT, but every cartridge I have used over the past 3 or 4 years has developed a leak after using it one time. I had suspected that the problem might be the stove or lantern. But these leaks occur with whatever "appliance" I use. I have the two burner backpack stove, the backpack lantern, a single burner stove and a suitcase Stove/Grill combo. The symptoms are that I use a "NOS" cartridge in whatever appliance. Works fine etc. But when I remove the cartridge, it will leak. Sometimes with a visible plume of propane/butane gas. NOT a SAFE situation. This started 4-6 years ago, with the most obvious leakage being at the California Stove Gathering #5 in 2012. All my cartridges were probably at least 5+ years old at the time. Prior to that I had suspected a problem. At CASG 5, there was a visible plume of vapor. At that point I knew something was wrong when 2 cartridges I had partially used leaked so strongly that I left them near the garbage dumpster rather than put them in my car for the trip home. They were venting quite visible white gas fumes when I left them. My usual method of "Saving" these cartridges was to screw them into my lantern which seemed to keep the cartridge from leaking while allowing me to use the fuel as opportunity permits. This will no longer be my preferred method, at least if I store the cartridge inside my residence. The reason this "saving" method will no longer be used and the reason for this post is that this weekend, I was puttering around my garage, coincidentally I smelled the telltale odor of propane. I was standing next to where my lantern was stored, which was most recently used and kept "plugged in", because of leakage, at the Joshua tree CASG this spring 2014. I am in my garage quite often so I am guessing I did not notice before since it was either "all of a sudden" or it was a tiny leak that got worse over time. In other words it can happen any time with little or no warning. I checked the lantern and heard a tiny hiss of leaking gas. No amount of tweaking and twiddling, very technical procedures, would stop the leak. So I took the lantern outside and let it leak in relative safety on my back porch. I have not yet done a post mortem on this particular cartridge yet, but intend to do so maybe this weekend. I would guesstimate I have had perhaps 5 or 6 of these cartridges leak in the past, some of which could be "saved", but 2 or 3 which could not. The only symptom I visually saw a year or so back when I last pulled a leaky cartridge was that it appeared there was some plastic matter lodged in the opening of the cartridge. I assume this was some O ring material that had somehow been torn or dislodged from it's normal location. I posted some comments on this then I forget the posting but it was in response to Hiking Jim asking a question about life of these cartridges. Sorry for the long-winded post but this is important enough that I feel every owner of these cartridges inspect them for leakage,and SAFE Storage. I am guessing after enough time/aging, the seals on these cartridges become brittle and then fail when first put into service. Good Luck and "no go Boom" Jim Henderson
Good on you for posting that Jim. Tough that it's a resounding and final nail in the coffin for Powermax gear - feeding them isobutane through one of those adaptors doesn't replicate the effect of the original, high-propane percentage mixture I feel, though it gives an impression of how it was in the good old days before the kit and carts became obsolete. John
https://classiccampstoves.com/posts/99238 This page was where I first commented about suspected leaks. 2009. Jim Henderson
So sad. I do appreciate the long winded post. Could that be why Coleman discontinued the Powermax line??? Flimsy cartridge... high % of propane. Ken in NC
I replaced the black plastic 'Thingamabob' inside the valve assembly on one of my Powermaxes, as it was crumbling, and not sealing very well. I've also had at least one cartridge refuse to let fuel out when installed in a stove. No leaks yet...
BTW my cartridges have been stored in my garage all these years with no protection from heat. Often in the summer my garage temperature may be just over 100. Never gets close to freezing. Heat is a well known factor in plastic degradation, ie decreased lifetime. So maybe if your cartridges do not see temperature extremes, yours will last longer than mine. BTW I also stored many standard Lindal type cartridges and Gaz resealables and even the piercables alongside (same storage conditions) the Powermax with absolutely no problems so far. The piercables go back as far as the 70s but there is nothing to fail other than the metal can itself. The Lindals are a mix of brands typical at sporting supply stores, and of various ages including as old as the Colemans. The Gaz resealables are the same. Jim Henderson
Hopefully my last post on this thread. I contacted Coleman customer support via email to alert them to the hazard. I suppose since the product is out of production, their interest/concern level is low. I was disappointed at their reply but not unexpected. Best they could do was offer me a discount of 25%. I suppose that could make the new Gladiator 2 burner stove in a different thread https://classiccampstoves.com/threads/27735 more affordable, yes? Only $150 instead of $200 ;^) I really wasn't looking for a discount or anything, just a level of concern for their numerous faithful fans. Ah well, at least some of us stovies are alerted to the potential hazard with these aging canisters. From now on I think I will try as hard as possible to use up any canisters as soon as I start them. I did try lubricating the nipple and even the O ring, but no difference on other canisters, ie didn't seem to prevent new leaky canisters. BTW the leaky canister is now fully empty. I left it plugged in to the Powermax lantern on my back porch and it bled off during the week. Maybe one more post if I have time to cut the valve area open and find anything of interest. Jim Henderson
My last post unless something new pops up. I cut apart the leaky cartridge. First, Indeed it was totally empty, having evidently slowly leaked out on my porch over the week. I found nothing odd inside the can, other than the plastic tube was somewhat loose (it fell off while laying on my work bench) in it's connection to the valve assembly. Maybe this allowed the tube to slip off the valve and then prevent liquid fee of fuel and revert to vapor gas feed. This might be what was causing some of the cold weather problems some of us have noted. BTW, I have seen at least 3 different designs for the internal tubing and weight assembly. OUT OF CURIOSITY I INSPECTED A NEW NEVER USED CARTRIDGE. RESULTS AS FOLLOWS... I inspected the valve area with a magnifier and light and saw the same black material I saw on all previous occasions with leaky cartridges. This time I picked out the black stuff and to my surprise it was a perfectly formed tiny O ring that had twisted itself into a pretzel over time, much like rubber bands will twist into odd shapes as they age. The O ring is wild guesstimate about 1/16th inch diameter and flat. I am guessing this O ring sits around the valve opening and is expected to slip over the appliance needle for a seal. Instead the O ring must come loose from whatever holds it in place and then gets stuck across the opening of the valve and apparently either causes a leak and or prevents a good seal with the nipple. I am guessing the tiny O ring is part of the larger O ring that I believe seals the body of the valve and is visible around the inside edge of the valve opening. I am guessing here. That or it is punched out of the overall seal when first used and then becomes a problem. So FWIW, that is what I have found. I could if I get ambitious, look at all my remaining never used cartridges to see if the O ring is in place and or whether it has twisted over time. If I see anything interesting and if I make the effort, I will post the findings. Jim Henderson PS thoughts. Seeing the O ring may offer some field expedient fixes to continue using a cartridge... Use a needle to pick out the O ring and I believe the cartridge will either stop leaking or allow continued use. The caution is that flammable gas will probably be venting while you poke around. OR, once you install a cartridge do not disconnect it until fully consumed. Sort of like the old piercable Campingaz cartridges.
I know this is an ancient post but 15 years after discontinuation I'm finally exploring Powermax stoves lol. And due to having old NOS cartridges this concerns me. I wonder if hitting the nozzle with a light dusting of silicone lube might help, potentially allowing the o-rings to slip by rather than catch and twist.
You will notice the bad seal only after you remove the cartridge from the stove. They have a tendency to stick open. I have the same problem as you and it comes down to how they were stored. Also whenever I open the container that they are stored in there is always the hint of fuel smell, so minute amounts are leaking. Since I have the canister adapters, I just need to spend the summer using up all the fuel I have.
Oh they are certainly concerned as far as product liability and lawsuits. That never fully goes away.
I have an old MSR canister that I used a few weeks ago and I have to leave the stove attached. A canister that wasn’t stored well, paint faded, obtained thru a recycling center. I have a ton of Powermax canisters, should use them up. Duane
