Thermos flask

[carlton23]

My wife put ice in a thermos flask to put in cold drinks but the flask broke. I understood you could do this. Why did it happen, can anyone explain?

[wildwood]

As we have been using them with crushed ice for more years than I care to remember. I can only presume that your good lady dropped cubes in and broke the inner skin which is very thin in domestic flasks. Maybe there was a hairline fracture from a fall before and the ice broke the 'camel's back'. Drooping a vacuum flask weakens the neck of the inner which is where it is supported.
The latest one we got has a very wide neck to accommodate putting in the ice.

[carlton23]

Wildwood, I did ask my wife this at the time but of course she denied dropping ice into it. Ah well .......!!!!!