[AJ]

I keep my resin just wrapped up in the bag it came in. Its in the garage which has no damp and is not in sunlight.    It doesn't seem to be lasting very long in the canister. it does seem quite dry, as in, it doesn't stick together and is almost powdery, if you know what I mean.
I wondered how long it can keep for in these conditions. I've had this bag for about 5mths.

[DASERVICES]

Resin can last up to 2 yrs in the correct conditions with bag sealed air tight. It looks as if your resin has dried out so when water is added it is cracking.

It also depends what resin you are using. It looks like your resin has been exposed somehow.

Looking at the spec of resin I have spotted something I have never seen before, to add water keeping it moist. Need to look into this.