Shelf-life of Araldite?

I went to use my trusty Araldite only to find that the tops would not unscrew, and my attempts to do it were twisting up the tubes themselves, with a rupture likely.
How long have I had it?
I don't know, but the price, which is printed as part of the box, and not as an add-on sticky label, is given as, "6/-"
So, then I turned to my "Rapid Araldite", where the price WAS on a sticky label as 86p (which is 2.8 times the price of the previous), and it is suffering from the same twist-up-the-tube-and-not-unscrew-the-cap problem.
In both cases, I'd always been very careful to keep the two tubes separate from each other, and not to mix up the caps, with the two tubes stored opposite ways into the box, so perhaps there is a sell-by date / shelf life limitation for this product?

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I have had a similar problem when the tubes are cold. These materials are very viscous when cold and the tube will bend, distort and even rupture when unscrewed. If you warm them up to circa 30 degrees the caps come off relatively easily. I now always buy epoxy in a pack which has a double syringe since it eliminates this problem. Regards Mike

mike wrote:
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Quite agree. pop the tubes in a mug of warm tap water and not only do the caps come off with ease but it is also easier to mix. Bob

Still have some tubes from the late 60's that have had stiff tops for years.
Just pop them, cap downwards, into a cup and fill with water from a well run hot tap, leave for a couple of minutes, dry off, and the tops will come off with no problem, but just watch as the contents will be quite runny - this makes the mixing far easier.
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Paul Bernard wrote:
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Bit of an echo in this thread!!! Still it was a top poster- lol
Bob

On Fri, 3 Apr 2009 20:22:44 +0100, "Paul Bernard"
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Ooh, be very careful when doing this. One *very* important bit of safety advice here: don't use one out of her best crockery set.