Why did the UK persevere with glass vacuum flasks for so long when stanley steel ones existed since 1915.

[PT1029]

Not as retro as one I have: -

It had regular use in the 1980's - fell out of my saddle bag onto the road. Landed on the lid which crumpled, glass survived so I was able to drink the contents at lunch!
Trying to find a good home (museum?) for it as I don't use itt hese days.

[Bmblbzzz]

How old is it? I note "English patent" rather than British or UK, also "Foreign": could be 1950s?

Impressive that the glass survived the drop.

[PT1029]

The lid says 1925 (approx 7 o'clock position on the lid).
Of course, well ahead of its time - it also says "Foreign".........!

[SA_SA_SA]

There being no foreign countries in the decades since its manufacture? Now it would simply have country of manufacture on it, an improvement surely.

[Bmblbzzz]

The lid says 1925 (approx 7 o'clock position on the lid).
Of course, well ahead of its time - it also says "Foreign".........!

Well spotted. 97 years old!

[Nearholmer]

I’m pretty sure that English patents ceased to exist deep back in Victorian times. I’ve consulted a lot of patents from the 1870s and 1880s, and they were all “British”.

Yep, checked and the separate English and Scottish systems ended in 1852.

Aha! It is a British Patent, so goodness knows why they called it English.

[Bmblbzzz]

Possibly they thought it sounded better for export markets? I'm thinking for instance of British motorbikes from at least the 1940s to the 1960s, which often had "Made in England" painted on them somewhere. Of course they were, most of the factories were around the West Midlands, but even so... (And yes, of course, very different products and markets).

[rogerzilla]

How old is it? I note "English patent" rather than British or UK

Pre-James I, then.

[Nearholmer]

I think we might be looking at a Model No.28 here.

This is from a 1929 advert:

What we don’t know, of course, is how long this model was made for (or remained as NOS in a shop with slow stock turnover). The 1925 date is that for the patent, not when it was made.

Maybe you should offer it back to Messrs Thermos for them to display in reception with a label claiming that it was in regular use for a century (in exchange for a top notch new one).

[PT1029]

Yes, that is the one. Incidentally the corrigated ribs on the case are in fact a thread, the aluminium top part screws into it.
Offering it to Thermos sounds a good idea. I think I would have to be homest and say intermittant use over nearly a century, but not regular use!
We did have a spare vacuum flask for ir (also copper coated). Alas that got binned in the sot out after dad died.
Also the outer did suffer corrosion (a few small holes at the bottom), so the inside of the case is (if I remmeber correctly) blue from some of my dad's resin car body repair stuff - after all, all cars in the 1960s/70s needed body repair stuff!

[Nearholmer]

The same ad shows another model, presumably a lot more expensive, where the body looks the same but is made entirely from brass, presumably to avoid the corrosion problem.

[Carlton green]

I guess that PT1029’s vintage flask used a cork (push-in) stopper rather than the long standard plastic threaded type. That would give a further reason to carry the flask upright.

The steel bodied flasks that I remember all rusted on the inside, the seal between the glass inner and carrier being not perfect allowed fluid to seep past it and then assist corrosion.

[Slowroad]

I acquired my metal flask some years ago after it was found after a house fire - I've dropped it several times but it still works fine...

[cc1085]

A story,
Many years ago people worked as a community, cutting turf or laying hedges, scything and saving hay etc. A fire would have to be lit for a tea break and people would exchange news and stories and have a social occasion. Then a new tech. arrived in the form of the vaccuum flask and that was the end all that as some sat in their own little corner and had a break on their own and didn't socialise anymore. New technology always has a downside and unimagined consequences.

[rogerzilla]

The steel ones aren't infallible. Water can get in between the flask and the casing, slosh around, and probably go stagnant. Washing one out with laundry detergent - SOP for removing stains from a teapot - is a bad idea as it taints the flask for days, again suggesting there are seams that don't get effectively flushed out.

Possibly the better branded ones are sealed more effectively than the usual Chinese knock-offs.