Well... crap! Maybe this is common knowledge but it was news to me and found out the hard way.
Evidently the chemical heaters have a "no matter how they are stored" shelf life of about 5-7 years and likely to be full on dead somewhere between 7-10yrs.
I had some that fairly recently had been taken out of MRE meals and unused. Trying to use one a couple days ago... it wouldn't fire up at all. I tried the salt trick, but to no avail. I tried 6 others and out of those only 1 actually had 1 bar out of 4 reach reasonable temps and a second partially, but it took a good 10-15min after adding water before they actually activated. Another... 1 bar got slightly warm but the other 4 heaters were completely dead.
Doing a bit of research I found some info citing 5-7years, regardless... which really set me off. I dug into my ammo boxes (where I had 16 sealed fifty packs of em) that I picked up 10-12 years ago. Pulled 2 our 3 out of 3 or 4 packs... and sure enough! Every single one of them was deader than a doornail! Worthless!
The majority of my life I've been using those tubed Vietnam era hexane tabs we've had stockpiled by the case since I was just a young buck (50+ years old). They have always been reliable and somehow must have got it in my head that the chemical heaters would have a similarly long lifespan, if properly stored. NOPE!!
At least I recovered a couple ammo boxes for other uses, but it sure didn't make me happy tipping them all out into the trash bin.
Evidently the chemical heaters have a "no matter how they are stored" shelf life of about 5-7 years and likely to be full on dead somewhere between 7-10yrs.
I had some that fairly recently had been taken out of MRE meals and unused. Trying to use one a couple days ago... it wouldn't fire up at all. I tried the salt trick, but to no avail. I tried 6 others and out of those only 1 actually had 1 bar out of 4 reach reasonable temps and a second partially, but it took a good 10-15min after adding water before they actually activated. Another... 1 bar got slightly warm but the other 4 heaters were completely dead.
Doing a bit of research I found some info citing 5-7years, regardless... which really set me off. I dug into my ammo boxes (where I had 16 sealed fifty packs of em) that I picked up 10-12 years ago. Pulled 2 our 3 out of 3 or 4 packs... and sure enough! Every single one of them was deader than a doornail! Worthless!
The majority of my life I've been using those tubed Vietnam era hexane tabs we've had stockpiled by the case since I was just a young buck (50+ years old). They have always been reliable and somehow must have got it in my head that the chemical heaters would have a similarly long lifespan, if properly stored. NOPE!!
At least I recovered a couple ammo boxes for other uses, but it sure didn't make me happy tipping them all out into the trash bin.