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Post by jonjel on Nov 12, 2014 11:05:40 GMT 1
A couple of years ago I was bought a couple of hand-warmers for when I go to rugby or other cold venues. And they are great. The comprise a liquid in a bag which also contains a small bi-metal type strip. When you 'snap' the strip in one direction or another the liquid slowly turns to a semi-solid crystalline structure releasing heat.
To regenerate these you put them in boiling water for a round 10 minutes, let them cool and bingo, start all over again.
Last night I thought I would re-generate them and stuck them both in a pan on the wood burner. They were simmered for a lot more than 10 minutes and allowed to cool.
However, only one wanted to revert to being liquid, and usable.
Anyone got any ideas as to why?
Do these things have a life of so many cycles?
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