"vacuum" flasks

On Fri, 27 Feb 2004 18:44:03 +0000, Brian wrote:

Just back from "Tesco"s Couldn't decide on whether a 0.5L flask, or a 1.0L flask would be a better
buy - So I bought one of each! The 1.0L one I'll test tomorrow as I take it to work, and the 0.5L
I'll test on my day off this week as I'm planning a bit of hill walking. So I now have a nice little
family of flasks, a 0.35L one for soup, and now a 0.5L and a 1.0L. Funnily enough, my nickname at my
archery club is "Sir Brian of Flask" - looks like I'm living up to my name!

Sent an email to the manufacturers of the Aztec flask - will see what they have to say.

--
Brian

(Collector of flasks)

In message <[email hidden]>, Brian
<[email hidden]> writes

Quoted message said:

I don't suppose any of you guys could recommend a decent brand of "vacuum" flask?

My 5 month old "Aztec" 1 litre stainless steel flask is now no longer keeping things hot - when I
pour in a hot drink, the outside wall of the flask gets hot a half hour later :-(

Doesn't seem right to me... I did get a replacement stopper free of charge from the manufacturer as
the rubber o-ring had perished, but even with the new stopper the outer wall is still getting hot.

I've got a fantastic steel flask that is now over ten years old. The contents are still quite hot 36
hours later. The bad news is that I have no idea what make it is, as it was a birthday present and
has no markings on it - except for a fair number of scratches and dents.

--
Martin Richardson
216/284 Munros (34/34 'Furths'😉
217/89 Donalds 397/1552 Marilyns 439/439 Nuttalls

Quoted message said:

Not being in the habit if falling over (touch wood), I've never actually broken a glass flask.

Iused to cycle to work and my grab rack had a habit of spitting the thermos's out every time I went
over a bump - eventually I learned to tie them on but for a while I got through about one a week :-)

--
Boo

Brian said:

--
Brian

(Collector of flasks)

Erm.... I think I'm up to 9 flasks now!

Our local Tesco has just had a special offer. A 1.8 litre and a .5 litre Thermos bundled together
for £3.99. I couldn't resist. I've only used the .5 litre, so far, and it was good. Too bulky (and
breakable) to stick in a rucksack, though.

My Aladdin 1 litre Stainless Steel flask seems to be deteriorating after about 10 years but it could
just be because I didn't pre-heat it for long enough. It used to be amazing. I would leave it in the
car while I did a day's walking then have to blow on the tea to cool it down to drink; I hope it's
not wearing out :-(

Judith (Off to check if there's a flask ng)

On Sat, 28 Feb 2004 16:06:21 -0000, "Rifleman" <[email hidden]>

Quoted message said:

Do you prime it first, with boiling water? You have to pre-heat S/S flasks for them to work
properly.

I never prime mine and it works fine. I've just finished the contents of my flask, made at 8 this
morning, half drunk at about 2. The rest was still hot enough that I couldn't drink it until I'd
left it to cool for a while.

"Andy Howell" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Fran said:

Quite. I've never had any problems with mine. I've got two stainless steel flasks, and they're
both brilliant. Much better than the lottery with the glass getting in the water.

I've got two, a small one and a larger size, stainless steel flasks. The larger one is superb and
keeps soup and stuff hot for most of a good day's walking. The smaller one is not do good and will
be getting a little too lunkewarm by lunchtime. Both are far better for filling with boiling

water

Quoted message said:

for 5 minutes before putting in you chosen liquid.

Ok looks like the 1 litre flasks are more likely to perform adequately - mibbe that's where I've
been going wrong as I never take more than .5L. However, unless there are some "specfic" heat
properties which affect my conclusion, surely a glass 1L would still be better than a SS 1L?

Recommended makes seem to be Atlas, Salewa and Zojrushi - and avoid fancy
lids.

druidh

[email hidden] said...

Quoted message said:

Recommended makes seem to be Atlas, Salewa and Zojrushi - and avoid fancy
lids.

<Cautious> I've never had any problems with either of my two 'fancy'
lids. Neither of my SS flasks were expensive: one was a freebie from a certain motoring
organisation and the other was a cheapie in Poundstretcher.
--
Fran If you need my email address please ask.

Chris Townsend said:

In message <[email hidden]>, John Laird <nospam@laird-
towers.org.uk> writes

Quoted message said:

On Sat, 28 Feb 2004 17:37:10 +0000, Gordon <[email hidden]> wrote:

Quoted message said:

Quoted message said:

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Harry Newton <[email hidden]> wrote

Quoted message said:

Quoted message said:

Quoted message said:

>'Trail' did a review of SS flasks a few months back, and based on that I got a Vango 1 litre.
>This is far better than the Aladdin I used before this.
>
>I think the main problem is that some (all ?) of the 'click to pour' lids let out heat quickly.
>The new flash has a better design: one of the 'half unscrew to pour' stoppers.

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That's the type of top which leaks on mine, and doesn't pour very well. No name on it - so it
could be a cheap one I suppose.

Quoted message said:

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I have a "Tatonka" (bought for me, I hasten to add) 1l flask and a genuine Thermos 0.5l one. The
larger one pours copiously when the cap is partly unscrewed, the smaller has a tab that levers up
a seal underneath, allowing a dribble from the top. Mind you, the cup size on a 0.5l flask is so
small that a dribble is quite adequate - it reminds me of my daughter's toy tea sets. I bought
the small flask because I quite like carrying a modicum of hot drink in addition to a Sigg bottle
of squash.

I don't find keeping either upright all that difficult, but I don't think they leak easily anyway.

Quoted message said:

I did a test for TGO a couple of years ago, checking contents temperature after 4, 8, 12 and 24
hours. There was no discernible difference between flasks after 4 hours but there was after 8
though even after 12 the water was still pretty hot (highest 91C, lowest 74C). The best results
came from the 1 litre Salewa Thermo Star. Of the half-litre flasks the Zojirushi Tuffslim Compact
and Aladdin Stanley were pretty good. I found, unsurprisingly, that smaller flasks cooled down
slightly faster than large ones.

Quoted message said:

When choosing a flask I think weight and type of lid matter more than heat retention, as they are
all pretty good at the latter. The heaviest 1 litre flask I tested weighed 770 grams, the lightest
585 grams. Some of the flasks were hard to pour from without removing the cap, which of course
leads to the contents cooling more quickly.

I tested half a dozen a few years ago, just random samples picked from campers who were starting off
from our house, some glass, some steel, and found that the largest difference between them was the
efficiency of the stopper in heat retention. Some were very good, some were terrible, and the rate
at which they lost heat seemed to correlate well with the conductivity of the stopper. Easily tested
-- fill flask with boiling water, seal, leave for half an hour, take of cap, leaving stopper in,
measure temperature of top of stopper. The worst were those where the stopper was simply a hollow
plastic plug, with free air circulating inside, no attempt at internal insulation. So stupid.
Slicing the top off, stuffing it with cotton wool, and gluing the top back, made a big difference to
the performance of one of the worst offenders, which happened to be mine.
--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
["]http://www.dai.ed.ac.uk/homes/cam/]

"druidh" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Ok looks like the 1 litre flasks are more likely to perform adequately - mibbe that's where I've
been going wrong as I never take more than .5L. However, unless there are some "specfic" heat
properties which affect my conclusion, surely a glass 1L would still be better than a SS 1L?

// snipped //

druidh

Thermal conductivity of steel may be about 50 - 100 times that of glass, but that is only relevant
round the neck. As the area of the stopper is relatively large, heat loss through the containment
vessel at its neck (as distinct from loss through the stopper) is probably a second order effect.

Significant heat loss will occur through infrared radiation between the two layers of the vacuum
vessel It is possible that well silvered glass may in this respect perform better than stainless
steel. Perhaps someone here has the facts?

Because of the relationship between volume and surface area of a containment vessel, larger vessels
will perform better than small ones. I remember a New Zealander saying that one gallon steel flasks
work well in the Antarctic.

I agree with earlier comments that there will be poor steel flasks which perform badly. But there
are good ones. I have had excellent performance from 1 litre stainless steel flasks at temperatures
below -20 º Celsius. Such temperatures are rare in this country. 1 litre stainless steel flasks are
now down to about 500 g in weight. A glass flask will most probably weigh more than that.

--
Alan Law

Brian said:

I don't suppose any of you guys could recommend a decent brand of "vacuum" flask?

Reviews in Trail & TGO (referred to elsewhere in this thread):

TGO Dec 2002 p.87 (Chris Townsend) Trail Dec 2003 p.73

Will supply photocopy to original poster for a suitable donation to suitable charity.

Allan

In article <[email hidden]>, Chris Malcolm <[email hidden]> writes

Quoted message said:

Some were very good, some were terrible, and the rate at which they lost heat seemed to correlate
well with the conductivity of the stopper. Easily tested -- fill flask with boiling water, seal,
leave for half an hour, take of cap, leaving stopper in, measure temperature of top of stopper. The
worst were those where the stopper was simply a hollow plastic plug, with free air circulating
inside, no attempt at internal insulation. So stupid. Slicing the top off, stuffing it with cotton
wool, and gluing the top back, made a big difference to the performance of one of the worst
offenders, which happened to be mine.

Thanks for the tip. I might have just found a use for the remains of a tin of No More Big Gaps - low
expanding foam!

When I get a round tuit I am going to drill into all the flask stoppers I have and fill them up with
foam if they are not already full. Drilling a hole a couple of mm bigger than the foam nozzle from
the topside should be easy and not be structurally damaging. A dab of hot glue gun sludge on the top
and the job will be a good un.

--

dscs.demon.co.ukdscs.demon.co.ukOpen ↗

Quoted message said:

In article <[email hidden]>, Chris Malcolm <[email hidden]> writes

Quoted message said:

Some were very good, some were terrible, and the rate at which they lost heat seemed to correlate
well with the conductivity of the stopper. Easily tested -- fill flask with boiling water, seal,
leave for half an hour, take of cap, leaving stopper in, measure temperature of top of stopper.
The worst were those where the stopper was simply a hollow plastic plug, with free air circulating
inside, no attempt at internal insulation. So stupid. Slicing the top off, stuffing it with cotton
wool, and gluing the top back, made a big difference to the performance of one of the worst
offenders, which happened to be mine.

Thanks for the tip. I might have just found a use for the remains of a tin of No More Big Gaps -
low expanding foam!

When I get a round tuit I am going to drill into all the flask stoppers I have and fill them up
with foam if they are not already full. Drilling a hole a couple of mm bigger than the foam nozzle
from the topside should be easy and not be structurally damaging. A dab of hot glue gun sludge on
the top and the job will be a good un.

Umm. I reckon Rapid Araldite would be a better glue for finishing off.

--
79.84% of all statistics are made up on the spot. The other 42% are made up later on. In Warwick -
looking at flat fields and that includes the castle.

Quoted message said:

In article <[email hidden]>, Chris Malcolm <[email hidden]> writes

Quoted message said:

Some were very good, some were terrible, and the rate at which they lost heat seemed to correlate
well with the conductivity of the stopper. Easily tested -- fill flask with boiling water, seal,
leave for half an hour, take of cap, leaving stopper in, measure temperature of top of stopper.
The worst were those where the stopper was simply a hollow plastic plug, with free air circulating
inside, no attempt at internal insulation. So stupid. Slicing the top off, stuffing it with cotton
wool, and gluing the top back, made a big difference to the performance of one of the worst
offenders, which happened to be mine.

Quoted message said:

Thanks for the tip. I might have just found a use for the remains of a tin of No More Big Gaps -
low expanding foam!

Quoted message said:

When I get a round tuit I am going to drill into all the flask stoppers I have and fill them up
with foam if they are not already full. Drilling a hole a couple of mm bigger than the foam nozzle
from the topside should be easy and not be structurally damaging. A dab of hot glue gun sludge on
the top and the job will be a good un.

It might also help keeping a bit of scrumpled cloth like a hanky in the cup. Even when well filled,
the stopper can still be a weak point in the insulation.

--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
["]http://www.dai.ed.ac.uk/homes/cam/]

Chris Malcolm <[email hidden]> wrote

Quoted message said:

It might also help keeping a bit of scrumpled cloth like a hanky in the cup. Even when well filled,
the stopper can still be a weak point in the insulation.

then you can wipe the cup with it after use and stop coffee/sticky drink getting on the threads.
--
Gordon

Judith said:

Brian said:

--
Brian

(Collector of flasks)

Erm.... I think I'm up to 9 flasks now!

Our local Tesco has just had a special offer. A 1.8 litre and a .5 litre Thermos bundled together
for £3.99. I couldn't resist. I've only used the .5 litre, so far, and it was good. Too bulky (and
breakable) to stick in a rucksack, though.

My Aladdin 1 litre Stainless Steel flask seems to be deteriorating after about 10 years but it
could just be because I didn't pre-heat it for long enough. It used to be amazing. I would leave
it in the car while I did a day's walking then have to blow on the tea to cool it down to drink; I
hope it's not wearing out :-(

Judith (Off to check if there's a flask ng)

I had a lucky find today, the neoprene cover of my 0.5L "California Innovations" plastic water
bottle (a cheap buy at Woolworths) snugly fits the 0.5L Tesco Stainless Steel flask... I had the
water bottle for ages, only when I was going to get my flask out of the cupboard that I noticed it,
thought i'd try it on for size, and was surprised when it fitted! So now I have a nice cover for the
flask, which will save it getting scratched!
:-D

--
Brian

Brian said:

So now I have a nice cover for the flask, which will save it getting scratched!

It's a bit late for my 350ml (Asda) SS flask. It bounced out of the car and rolled half way down the
road. It now has some "characterful" dents. Still, it didn't break and the tea was still hot!

Judith

Had an Aztec since 1998 - great bit of kit

Richard Webb

Quoted message said:

Nonononono, you just leave the water in the flask, and add the tea or coffee when needed.

Fruit teas... The blackcurrent is great on a winter's day

Mint for summer

Richard Webb

In article <[email hidden]>,
Brian <[email hidden]> writes

Quoted message said:

I might get in touch with the makers of the flask, and see
if they will exchange for a new one, after all it's
supposed to have a 10 year warranty. (They did replace the
stopper free of charge, so hopefully they should replace
the flask as it's faulty)

The inner flask and outer must be touching causing the loss
of heat via the outer skin. The flask shouldn't get hot!

I bought a Coleman stainless steel flask from Blacks. This
developed a heat loss and the flask was replaced no probs.
--
Bill Grey billboy.co.ukbillboy.co.ukOpen ↗

W. D. Grey said:

In article <[email hidden]>,
Brian <[email hidden]> writes

Quoted message said:

I might get in touch with the makers of the flask, and see
if they will exchange for a new one, after all it's
supposed to have a 10 year warranty. (They did replace the
stopper free of charge, so hopefully they should replace
the flask as it's faulty)

The inner flask and outer must be touching causing the
loss of heat via the outer skin. The flask shouldn't
get hot!

I bought a Coleman stainless steel flask from Blacks. This
developed a heat loss and the flask was replaced no probs.

Well, the flask will be getting sent off to the
manufacturers by post tomorrow.

--
Brian