Epoxy activator shelf life

I still have a half gallon of epoxy and activator that was opened 10 months ago. How do I know if the activator is still good? I will do a test spray, but wanted to know what to look for to find out if it is curing correctly. When activator goes bad, what is the proper disposal method?
 
I dont have a lot of experience, but I will try. Landfill rules for haz mat are different in every county. You local landfill may have a provision for recieving hazzardous material. I have also added kitty litter or sawdust to a liquid waste until it became a solid and they just treated it as a solid waste. Our landfill allows that will paint products. If you do a test spray and it dries fast, it should be working. 10 months should not be a problem,
 
Up to recently I used PPG DPLF epoxy and activator. I would get a little over a year shelf life with the activator after opened when storing in a cool basement. When it started to 'turn', it became noticeably darker in color.
Not sure about SPI, but storage, amount left in can vs. air and moisture exposure play a factor in shelf life.
 
I've had SPI activator turn dark, but it never fails to activate the epoxy. If there's doubt, mix a little and smear it on a piece of metal. Depending on temps, it should be sandable in 24 hrs. If you don't have a solvent recycler, you can always mix the activator with some primer and leave it somewhere warm until it solidifies and the solvents evaporate, which might take a good long time. The dry puck is less hazardous than the liquid activator.
 
I purchased a gallon of SPI epoxy primer and activator in the spring of 2010. I split the part A gallon into quarts and turn the cans over every month (OK, almost every month). I opened and used some of a quart of the Part A and part of the gallon of Part B activator right away. Before re-capping the activator I gave it a shot of Bloxygen (canned Nitrogen). Some weird health issues prevented me from painting much for several years but I used more of the epoxy and activator every year through 2013. It worked perfectly but I worried it might be pushing my luck. In 2013 I purchased three quart cans of Part B Activator and used it with no problems. Two weeks ago I made another batch using the new activator and it worked like a charm.

Paint is stored in my South Florida garage in a cabinet. The garage is insulated and air conditioned most days (I'm retired and work out there all the time). It hasn't gotten below 60 in the garage for most of the last 20 years and definitely not below 70 or above 85 since the epoxy has been stored there.

I'm not saying this will be everyone's experience, especially if the storage area gets close to or below freezing or above 100 but mine has been that a year on the shelf wouldn't phase any of the SPI products I've used. My experience is limited to black epoxy primer and Universal Clear. I'm not sure the Bloxygen is necessary but it makes me feel better.
 
In 20 years, I have only known the epoxy activator to go bad twice around the 3 year mark and in that time it was left in cold and high heat in summer in both shops.
BUT I have experience two more calls where same deal it has gotten weak in 2 years.

Bottom line is we use to say 3 years once opened, now we say 2 years as we have no control over how it is stored.
Stable temps and the use of nitrogen would change everything.
 
It was stored in the house through the winter. Have been turning the part a can over a couple times. I will give it a test, and go ahead and use it, just not in a visible area.
 
as far as disposal though, mix it in old paint to make it hard and dispose of it that way. Liquids are problems, but rubber balls are not.
 
Ran into an issue this week with some black SPI epoxy purchased back in 2008. Bought it back then to prime over bare fiberglass on a 59 Vette convertible top lid and trunk lid. Used it then and had no problems at all. Both the primer and activator have been stored in the house in a controlled temperature. Had planned on repainting the car and changing out those two pieces when I did. Didn't get around to actually starting on the car until now and there's a few places on the car that needed taken back down to bare glass. After cleaning the surface with the SPI water based grease and wax remover, it was a couple of days before I sprayed it. Well, it's not doing right at all. It's dry to the touch but it's not even attempting to harden. Also, it has a weird look to it, almost like something is bleeding through but there's nothing here. When the car was painted back in 1991, it was sprayed with gel coat but I sanded through it to the bare fiberglass. I don't think it's the fiberglass because I also sprayed the fresh air vent lid and it's aluminum. It's not right either. I've about come to the conclusion the activator is bad. Is 8 years too long to store the activator even if it's been in a controlled environment?
 
New activator will take car of that, activator is way to old.
Activator good once opened for 2-3 years.
 
Another year has gone by, and I still haven't used the remaining epoxy.

Bottom line is we use to say 3 years once opened, now we say 2 years as we have no control over how it is stored.
Stable temps and the use of nitrogen would change everything.

Going on 2 years since I opened this can (stored in my house). Sounds like it should be O.K. What kind of adhesion test should I do first to find out if the epoxy is still good?

I will be spraying my truck cab with epoxy in about 2 weeks. Planning on using up the old epoxy for the floor pan and firewall. However, I recently ordered a new quart of epoxy for the exterior of the cab. Would like to use up the old stuff if I can.
 
Should be fine but mix a little and spray a test make sure drys over night.
Grab can and give two shakes before opening.
 
I know you are concerned about the hardner, but have you stirred the part A at all? If not the bottom of the can is probably like half set concrete. I know SPI doesnt(or didnt in the past anyhow) recommend putting the Epoxy on a shaker, but after it sits that long, its about the only way I found to "bust it up".
My cheap HF shaker died this spring, and I have been meaning to figure out what I am going to do about it since. A few weeks ago I found myself having to use some 2K primer I had laying around for a while, and 10 minutes into a 45 minute process of manually loosening that stuff up I was on Amazon ordering a Blair Tornado, LOL...
 
I know you are concerned about the hardner, but have you stirred the part A at all? If not the bottom of the can is probably like half set concrete. I know SPI doesnt(or didnt in the past anyhow) recommend putting the Epoxy on a shaker, but after it sits that long, its about the only way I found to "bust it up".
Thanks Barry. I have been turning part A over every few months. For the last 2 months, I have been turning it every few days. Sometime this weekend, I will give it a test.
 
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