Simmerlite in Extreme Cold

Priming, priming, and … O-rings.

The priming is obvious.
The O-rings bit is not.

Ordinary Viton O-rings are good to -15 F. Below that they are a bit hard and may not seal properly. They are good at the hot end though, to +400 F.

Ordinary Nitrile O-rings are good to -40 F, so they may be preferred at your temperatures. Not as good at the hot end though: only +225 F (107 C).

Silicone and fluorosilicone are better than Viton or Nitrile for temperature, but I am not sure the silicones like the hydrocarbon fuels very much. Fluorosilicones should be OK. Now try to find them.

There are others, but they too are harder to get.

Cheers

Thanks, Roger.

Yah, I hadn't even considered the O-rings! :-O

I often hear that the XGK is better in extreme cold than the Simmerlite and I'm trying to understand why.

Oh, by the way, what's the coldest temperature that you've used a Coleman Xtreme? I've had mine down to -5F without problems, but haven't had the opportunity to test it lower. I imagine you'd have to pre-warm the bottle, but I wonder what other limits you'd bump into…

Cheers,

-Mike

Hi Mike

> I often hear that the XGK is better in extreme cold than the Simmerlite and I'm trying to understand why.
Well, both have a preheat tube right in the flame to vaporise the fuel, so both 'should' work.

However, the Simmerlite is a quiet, respectable 'silent' burner, while the XGK is a raving extraverted machismo noise machine. Perhaps it is partly a mater of perception: the noisier the better?

And don't forget the priming instructions which come with the XGK: it should look like a football sized fireball. Yeah, seriously, that is in the MSR instructions! This approach may help get the XGK going faster and better.

I am not sure one will work much better than the other in reality if properly primed, except that the XGK can handle all sorts of fuels while the Simmerlite really only likes white gas.

Why the difference? It has to do with the jet size, the air flow arrangements and the type of burner used. High up in the mountains, or deep in the Antarctic, sometimes all fuels are a bit like kero! It may also be that the whole XGK gets stinking hot, while the open light Simmerlite does have parts out of reach of the flames which can cool down a bit.

The Powermax canisters should work down to -25 C (-13 F) by themselves. Below that the internal pressure is less than 1 atmosphere, and the gas does not come out. But as soon as you warm them a bit (cold liquid water is fine), they will rev up.

Coldest? Dunno. Not quite that cold. Thank you!

Cheers