I use a lot of glue around the home/shop. I got a gallon of the west systems stuff
Every time I've purchased marine-tex in the past few years, the jars have gone hard within a few months.
Interesting. I inherited a MarineTex kit off my deceased gunsmith. It'd be maybe five years old. I bedded an action about four months ago and other than being possibly higher viscosity when mixing it, it set perfectly well.