Is my epoxy defective, or is it just me?

[michika]

Yesterday I picked up a stick of epoxy. Today I cracked open the package, cut off a chunk and mixed it to the prescribed color. I followed the package instructions, and now after an hour, it still hasn't taken.

Its been about 2 years since I've used this stuff, so I'm assuming I've done something wrong. Yet at the same time I'm curious as to if epoxy can be defective, or stale to the point where its no longer usable?

I moulded the epoxy around an area of rock, and then pushed in my SPS frag. The epoxy never bonded to the rock, it made more of a mould of the rock surface. I didn't touch the frag as its fragile enough.

So what did I do wrong, and how can I make epoxy be my friend again?