I think that I would put some heavy gauge tin foil in the same pocket. I also think that MP puritabs would be smarter.

I fail to see why you couldn't boil water in a nalgene container. I wouldn't put it over a fire, but wouldn't have a problem dropping hot rocks into a container full of water until it was boiling.

I mean, if you can boil water in a canvas hat, it isn't going to kill a nalgene container. There is no evidence whatsoever that "toxins" will be released in this process.

That said, I carry stainless steel cups on the bottoms of my nalgene bottles, so I don't have to heat rocks.

Greg

OK, OK! So I had the figures wrong........ I too remembered from the book (not accurately). Still the point holds.

Jon

Did we miss our fibre this morning? LOL

Actually, I and I suspect most do as you say, carry a tin for boiling. Yes you can pour boiling water into a Nalgene bottle.

Jon

THANK YOU! Just buy one of those cups that fits on a nalgene bottle... basically no added space and minor added weight (especially if you go with Titanium).

You will be able to boil water quicker and safer! For an extra $6.50 and 150gm for the GSI Glacier Stainless Steel Bottle Mug or 130oz and $35 for the Vargo Titanium Mug which comes with a titanium cover!

I don't do fibre in the morning. Double expresso (2 cups) and a bacon butty with ketchup. - hold the polyunsatuates- thank you very much. Snarl!.
No, I am not Mr Nice Guy untill I have been caffinated and fed. <img src="/images/graemlins/smile.gif" alt="" />

OK, let's review.

When you heat water in paper, the water cools the paper below the waterline, allowing it continue to exist. This is possible not becuase paper is porus (you can, but shouldn't, do this in clayed paper) but becuase it doesn't melt.

Nalgene bottles melt. You have no way of acurately knowing how hot your drop rock is- 310-ish, you have a leaky bottle. Even if you could realiably determine the temperature of the rocks, it would be horribly inefficent. The difference of tempurature between 212 and 280 (safety margin) is relatively small when figured as energy (watts, newtons, whatever makes your hair stand up), and you would only be able to raise the tempurature of a very small mass of water with a stone. Sure, you could keep adding stones, but at that point you are basically pouring a mass of gravel into your water bottle. A comparitively large mass of heated gravel- you'd have more stones than water.

That ignores the long term exposure issues that lexan has to tempuratures over 240, IIRC. Water can not, at normal pressures, get above 212 degrees, so that's safe. But there is no way I can think of the boil water in a lexan vessel safely.

Excellent point. I once was watching someone demonstrate to a group of mechnical engineering students why they wear kevlar gloves when welding. Hit a glove with a torch. Fire deparment shows up five minutes later for the alarm activation.

Burning kevlar really stinks. I swear that the smell soaks into concrete.

ironraven,

Have you ever tried it? I haven't done it with a Nalgene bottle, but I have seen it done with canvas containers that could also not be placed over flame.

I don't think there is any chance in he__ that the rocks are going to melt the nalgene when you drop them into water. Is the process the most efficient? Heck no! But if you are trying to boil water in a Nalgene bottle, chances are your circumstances are far from ideal. Survival is about improvisation.

Tell you what, I have an older bottle that the lid doesn't completely seal on. I'll actually try it and report back. Then we will know, right?

Greg

It's not just that the paper/canvas/leather won't melt, it's that the heat transfer through the container (to the water behind) is fast enough to prevent it from reaching the temperature at which it would be damaged (or at least lose integrity). Porous materials have the added advantage that water soaking through it will also keep the surface close to water's boiling temperature.

Only experiments will prove it, but I suspect that the wall thickness and low thermal conductivity of polycarbonate (and the fact that the polycarbonate is not porous) would combine to make it unusable for boiling water over an open flame.