How can a steel thermos drinks flask fail?

Is it a steel or glass flask?

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My question was specifically directed to Neil ... in light of his observation

MichaelG.

Edited By Michael Gilligan on 09/11/2020 20:39:22

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It’s O.K. ...

Just for the record, I have had a 'Hot Stuff' branded (Vango??) stainless flask for the best part of 20 years and it still keeps drinks scalding hot all day (remnants are still luke warm next morning). It is definitely all stainless & vacuum insulated. It's just a shame that the matching cup is somewhere amongst the boulders at the foot of Cenotaph Corner in the Llanberis pass :-/

Hi Simon, it is stainless steel, glass ones don't often last long in working enviroments as they rattle about in the van or get knocked over.

Regards Nick.

I've was given as a present by my daughter one of the Stanley Master (Black) stainless steel flasks and this claims to keep contents hot for 24hrs. Certainly if not opened it is hot 24 hrs later.  Certainly I would expect it to perform at around £70.

I can make a hot drink at 6am one day and have a hot drink for breakfast next day when camping and away for a weekend.

Cant fault it.

Colin

Edited By Colin Heseltine on 09/11/2020 22:18:50

Easy - the vacuum leaked out

That’s funny - I’ve never ever come across a ‘leaking vacuum’. Where did it leak to?🙂

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I presume it was intended to be

MichaelG.

It'll be under the stairs, with the other one

They are

A CRAP

B JUNK

C Not worth a S-------T

Apart from that, they,re OK !

The simple point was that a vacuum never leaks away. There is nothing, by definition to leak to anywhere.

The only thing that can happen is for a fluid to leak into the space - generally, but not always, an air leak but most certainly not a vacuum leak. Lots think that vacuums leak but the simple truth is that those people don’t understand basic Physics.

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Surely the whole point is that Andy was joking

... The devilish smiley thing was a pretty good hint.

MichaelG.

No pressure to find an answer then..............
DaveD

I have two 1 litre Thermos flasks, that is Thermos make not cheap ones. Before filling with desired drink I pour boiling water in to heat them up. put top on and leave for a few minutes. Pour out and add drink, that way the drink is not heating the inside of the flask.

Pre-heating flask with boiling water before filling with same kept my contents of my flasks hot for longer than a day out. Unfortunately, they were condemned by insurance company after the fire and I’ve not been able to replace with same design.

I think that a larger volume of hot liquid in large flask, eg one litre, will remain hot for longer than water in half litre flask.

MCB

Surface area of a sphere is related to the square of the radius, while the volume is related to the cube of the radius. Simply put, that means the volume increases more than the surface area as the size increases.

That means a larger volume loses energy from a relatively smaller volume, resulting in less heat loss.

Regarding the comparison of ‘hot liquid’ to water may be misleading - there is likely greater heat content in some liquids (perhaps talking soups or other food-stuffs) than in the same volume of water. All to do with the particular specific heat of the liquid and heat losses at the same rate (at any particular temperature delta). A concentrated sugar solution would, of course, weigh far more than the same mass of water for instance.

We need ‘fair comparisons’ before making sweeping statements without qualification.

I think that's a sweeping generalisation

This exchange of humour brought back fond memories of my late father, a qualified Electrical Engineer with a successful and wide-ranging career. Clever chap, but he absolutely didn't get puns or satire!

Watching TV with dad I noticed he missed at least half the jokes. To him The Simpson's was just a kiddy cartoon, whereas I enjoyed the many grown up references to American and International Politics, the Hollywood machine, Media outlets, Celebrities, Gun Culture, Crime and much else. And I knew that some of it was over my head too; plenty of American celebrities and goings on don't make it over the Atlantic.

Likewise, I knew "Round the Horn" was rude, but listening to repeats carefully today, I find it's extremely rude, packed with naughty word-play I didn't understand in my youth!

Intelligence is very diverse. No one is good at everything and in my experience even the most unpromising types turn out to have spectacular skills. And I've met a few near geniuses who were incapable of ordinary life, for example a visiting senior scientist baffled by how to get a meal in a works canteen.

Dave

I just want to know where I can get some of that talking soup

( JOKE! )

I don't disagree with anything you have written

I only ever put boiling water in flasks so I can make the tea when I want to drink it. Making the tea in the flask would create problems cleaning it and the tea would be too strong (My late Mother would say that it would be "like beer" - sadly it was nothing like beer. I tried!

Incidentally, Denture Cleaner is excellent for removing tea stains from Stainless Steel teapots...... If anybody is interested.

MC