Toe warmers to heat cold fuel canister?

Nope, but I would think it would work. You shouldn't ever get to the max heat of the warmer, since you're heating something cold.

This trick works great if you're just out for a night or two. In fact, it seems Primus used to market reusable warming packs that affixed to the bottom of the canister with a plastic stand. The warmers are multi-use as well; use them to warm up your bag on a cold night, or to help dry out your shoes if you've been fording creeks and such.

> The toe warmers are claimed to put out maybe 90-100 F, and the canisters can handle 120 F, so
> it seems like this should work. Has anyone tried this, safely?

I do like the last word there.

Can I VERY STRONGLY recommend you do not try this? The toe warmers may not heat the canister to a dangerous temperature, but the pressure inside the canister will be very high and the stove will be roaring dangerously.

If you add the thermal feedback from the stove, then you could fairly easily reach bang temperature. Read the article on Exploding canisters before you go any further.

It is sufficient to pour COOL water over the canister. NOT warm or hot water!

Cheers

Roger,

Thanks for your reply, and even greater thanks for your article on exploding canisters. I somehow missed that fine 2007 article. For now, I'll try your cool water trick, and forget toe warmers.

Gary

Hi Gary

No worries. We just don't want to lose any paying members to unfortunate accidents! :-)

Cheers

Roger – I was out recently with my scouts and observed something new, kind of related to the question at hand.

I was finishing off a Gaz canister – so it was pretty much pure butane. And it was in the mid 20s F, so it wasn't burning very well.

I put it in a small pan of warm water (carefully, while it was burning) – and it leaped to life immediately.

The odd part was, for the initial 1-2 seconds the flame was pink. It was dark, so the pink was pretty obvious. I have never seen that before. The only explanation I can think of is that perhaps whatever mercaptans were left in the fuel came out of solution at the rapid heating and colored the flame. Even then, I don't know if this is a physical possibility.

Hi Don

Pink???
I will assume that 'pink' does not mean 'orange', which would mean some free carbon atoms were floating around.

Dunno, but I would like to know a bit more about exactly what odorants are used and what their chemical properties are. Very much so.

I would not discount the possibility. I don't think the idea violates any laws of physics or chemistry – that I know of.

Cheers

It was definitely pink, not the orange associated with incomplete combustion or poor fuel/air ratio.

I'll have to check to see which mercaptans are used in the fuel to determine if this theory is possible.

A lot of sulfur compounds have unique colors – such as hydrogen sulfide – so this is the only explanation I can think of.

But H2S doesn't burn pink.

We used to use CO2 canisters a lot back in my paintball days. Some guys tried using handwarmers to heat them up & increase performance during the colder months, but we found it was dangerous because they caused the gas pressure to vary wildly. Since I doubt that any canister stove is equipped with a pressure regulator, I think it would be dangerous to try heating them with toewarmers.

You're correct, H2S does not have a pink flame. I was merely pointing out that some sulfur compounds have unusual flame colors, and a possible explanation for the flame color I observed is the mercaptans (not H2S) added to the fuel as an odorant.

It has been a while (almost 15 years now) since I did some work at some sour gas wells. One of the requirements was safety training due to the very high H2S content of the gas. One of the videos mentioned and showed H2S burning, and if I recall correctly, is was some sort of purple color (and not very visible at that). But again, it has been a while, and I have slept since then, so it may have been another color.

Hi Don

I would be very interested in anything you can find about the odorants used.

I have found that different brands of canisters seem to have different odorants, and these leave different traces behind them. In some cases I am finding a greasy white residue (at room temp & pressure) which can clog the jet on the stove. I don't think it is the main odorant as the BP of mercaptans is generally low. Perhaps it is another contaminant.

Cheers