I was doing some testing of my V7 stoves, and had an original Coleman Powermax canister hooked up. This is listed as a 70% butane / 30% propane fuel. Since there was nothing to indicate otherwise, I assume that means 70% n-butane. The pressure/temperature figures support that.

I had stored the canister in the freezer for a day, so it was cold. Yes, there was some frost around the rim, which might be expected as I was testing indoors.

But when I disconnected the canister, it LEAKED! And I had tremendous troubles trying to get it to stop leaking. I ‘bounced’ the plug inside the valve several times, and it still leaked. OK, a bit of a dribble, but it was sure leaking. I have never had this problem in the field, even in the snow.

https://backpackinglight.com/wp-content/uploads/2024/08/Stove1_8.jpg (See Featured Image)

What caused this? There must have been something between the plug (red thing) and the rubber seal (purple bits). But the leak was (relatively) big, and the canister had been used before without any problems. I have to say that dirt does not seem likely.

I have used these canisters in the snow many times, and never had any problems. But I think I have always had the canister above zero C, either by keeping it in my pack next to my back and next to a water bottle which never froze, or by storing it overnight at the foot of my quilt. I don’t think I have ever seen frost on the canister in the field.

I am left to wonder whether taking the canister from the freezer into my office could have got ice inside the valve (Sydney has a humid climate, for sure). There was ice around the rim during this. Trying to flush any material out by bouncing the valve would probably not melt any ice as the fuel escaping was still sub-zero.

I may, possibly, have solved the leak by pressing down firmly on the top of the Lindal valve with a hot thumb. This might have restricted the flow of fuel and softened the ice just enough. Now that the canister has sat in the sun for a little while, it no longer leaks (and there is still fuel in the canister).

Has anyone had any experiences like this?

Cheers