Heating water in a plastic bottle

[twisted firestarter]

When I saw this video clip I doubted it would work but it does seem to. If you ever find yourself without a suitable recepticle to heat water you might want to consider this method...

http://www.youtube.com/watch?v=WZaKlPaE0mU

It doesn't say if the heated plastic taints the water which would be my only concern

 

[woodwalker]

its the same principle as boiling water in a paper bag I think, all the heat is conducted away from the paper into the water before it gets hot enough to ignite. I think the reason it needs no air is because air is a really bad conductor, so won't transfer the heat away from the plastic quick enough before it melts.

I think/hope I'm right Perhaps one of the physicists on here could clarify.

cheers for the link anyway though, I'll certainly be giving it a go. However wouldn't the plastic bottle explode?

woodwalker

 

[British Red]

Its perfectly possible to boi water in paper. Paper ignites at 451 degrees F - water far lower. The same is true of many plastics. If you heat them only to just above the boiling point of water, but not to the point at which they deform of boil, it'lll work.

One of those interesting facts (like lighting prawn crackers) possible but of limited use!

Red

 

[Gailainne]

Hmm creating a sealed vessel, filled with liquid with no place to expand too, and apply heat ! why do I think thats a baaaaad idea.

 

[Scots_Charles_River]

Boom.........

 

[Draven]

It's an interesting application of clever physics, but I wouldn't recommend it unless you want to get soaked in hot water...

Perhaps it would work better (safer) if you squeezed the bottle before filling it to the top. This would give the water room to expand (reducing the risk of the bottle exploding due to the pressure) while ensuring that there is still no air...

 

[wingstoo]

I did it in a plastic bag...

Same principle for doing it in a bottle just remember to take the top off.

LS

 

[ol smokey]

I don't know about heating water in a plastic bottle. But I did get an awful fright one time by pouring near boiling water into a small size lemonade bottle. Within a second or two the bottle suddenly shrank to a small tube and the water it had contained still near boiling point, Hit the ceiling and narrowly missed giving me a bad scald. I am sure that heating the water from cold would not do this but I am Posting this as a warning to anyone experimenting with hot water and plastic bottles

 

[Tadpole]

When I saw this video clip I doubted it would work but it does seem to. If you ever find yourself without a suitable recepticle to heat water you might want to consider this method...

http://www.youtube.com/watch?v=WZaKlPaE0mU

It doesn't say if the heated plastic taints the water which would be my only concern

the melting point of thermoplstaic polyamide bottle is anywhere between 130C and 260C add to that the thermal conductivity of the water removing the heat from the skin of the bottle, I’m pretty sure that it is less science and more about picking the right bottle to put on the fire. I would suggest that anyone, heating an enclosed vessel without knowing the amount of pressure it can take, is as dumb as a box of frogs

 

[Glen]

I don't know about heating water in a plastic bottle. But I did get an awful fright one time by pouring near boiling water into a small size lemonade bottle. Within a second or two the bottle suddenly shrank to a small tube and the water it had contained still near boiling point, Hit the ceiling and narrowly missed giving me a bad scald. I am sure that heating the water from cold would not do this but I am Posting this as a warning to anyone experimenting with hot water and plastic bottles

I've done similar in the past.

Possibly that's why the water bottle is full to brim in the video( water is fairly uncompresible whereas if there was air left in when opened there would be a larger release of pressure ) but I think the main thing may be that though he's heating the water its not up too boiling point.

 

[BOD]

I think Draven's suggestion - squeezing it to provide expansion room is sound.

As said it doesn't need to boil and if allowed to cool first it should be fine on opening.

Does anyone know how much water expands at 100 deg?

If it is incompressible is it also inexpandable?

 

[rich59]

So, could you make a reusable wooden cooking pot?

 

[Ogri the trog]

So, could you make a reusable wooden cooking pot?

I think it has already been done Rich - by processing the wood so thin that it becomes paper..... as mentioned in post 2

ATB

Ogri the trog

 

[gregorach]

I've heard of several cultures making cooking vessels from birch bark...

I don't think there's much danger of the bottle exploding - those bottles can handle a remarkable amound of pressure. What I would be worried about would be superheating the water - since it's under pressure, you can get it well over boiling point without it actually boiling. Then, when you take the top off and release the pressure, the superheated water inside explodes in a blast of steam and scalding hot water.

 

[woodwalker]

I've heard of several cultures making cooking vessels from birch bark...

I don't think there's much danger of the bottle exploding - those bottles can handle a remarkable amound of pressure. What I would be worried about would be superheating the water - since it's under pressure, you can get it well over boiling point without it actually boiling. Then, when you take the top off and release the pressure, the superheated water inside explodes in a blast of steam and scalding hot water.

Yeah, Apparently thats why you're supposed to take the tops of plastic bottles because if you don't bother recycling them and they go into landfill, they don't crush down, and therefore take up more room.

woodwalker

 

[kb31]

would the plastic not brake down some how and get in the water?
last ditch only i would't do it all the time

 

[Draven]

would the plastic not brake down some how and get in the water?

Speaking in the most basic of terms... no. Water is a solvent, but not that kind of solvent and not strong enough.
However, yes. Any liquid will undoubtedly be tainted by the container in which it is stored, especially if it's hot.

But personally, it doesn't really bother me. If you're having a cup of tea or coffee, I doubt you'd notice much.

 

[kb31]

i don't think it would kill you
i just would't do it all the time (chemicals)
if the bottle's full how do you know if it's boiled?

 

[Draven]

i don't think it would kill you
i just would't do it all the time (chemicals)

It certainly won't kill you. Most of the chemicals are relatively harmless unless consumed in large amounts, and there would only be trace amounts in the water. Although I'd imagine that it would be a bad idea to make every cup of tea that way