I had about a half quart of Nason epoxy and activator left over from about two years ago. I mixed it and shot the floor of my '37 in preparation for Lizard skin ceramic. I didn't really pay too much attention to the (dis)color of the activator when mixing it. Well... Almost immediately I noticed some issues after spraying. It didn't look "right", and honestly smelled funny. I'm fairly sure neither of them froze - shop is heated / cooled. Luckily, it wasn't the entire floor. So, does it all need to come off and shot with new stuff, or is a little extra cure time needed? Again, this will be all coated with Lizard, not finished / painted like a hood or anything like that.
Is it still tacky? It probably won't cure but there is no harm in leaving a little longer to see if it will get better. It will never be fully cured even if it firms up if the activator went bad but probably not a huge deal on an interior.
Your catalyst went bad. Probably not what you want to hear, but you’re going to need to take it all off and start over. Or you can leave it and waste more materials and time when it fails later.
Once you open up the activator it has a limited life time because you replace the portion you pored out with air and the activator degrades after that.
Epoxy activator isn't the same as urethane. I have kept epoxy for several years without problems. I would wait several days to see if it sets up. All you have to lose is a couple of days. I'm not saying the catalyst can't go bad but my exp. with epoxy has been very forgiving. Is there a chance someone put something in the container by mistake?
A couple things here, it's correct epoxy catalyst lasts way longer. Also, did you give the mix an induction period? Usually 10-20 min is normal based on temp. That gives the mix some time to begin the chemical reaction it requires. If you forget (I have, I'm not perfect) you'll find it stays wet longer. You might even get runs. It's possible your cat went bad but 2yrs isn't an insanely long time. How to fix, well you could wash it all off if it stayed soft, not wet, soft. You can also pull a rabbit out of your ass and spray 1 more coat with an extra dash of catalyst and let it kick all of it. Experiment on a small spot. Might save you a massive mess. Yes, I've done it before with success. Finally, for what reason was it used under lizard skin? I can point to cars with such products (or similar) that went over bare metal and, you guessed it, still there with no adhesion issues. It's inside. It's lizard skin. It's not even exposed to weather except some temp change. Just sayin, let us know what you did.
I would warm the shop up to about 80 degrees. I see you are in Canada so I assume it is still cool there. Turn on a fan to move air over it. Give it a day or so. Air movement is important with activated paints.
I did the same process the first time around on a different car. I probably should have started with new stuff, but lesson learned. Probably gave it 10 min to "mix" before I got busy. Nobody other than me has access to anything, so I'm 100% positive nothing got switched / added to said opened container. I shot it yesterday and there are a few barely tacky parts as on this afternoon. Lizard skin calls for non-bare metal (primer, etc) for application - it's their product, so who am I to argue? As I had patched some spots on the floor, I had bare metal. My luck isn't the greatest lately (like a one-legged man in an ass kicking contest) so I will be starting over. Luckily it isn't the entire floor. I'm in N.C.; not Canada by the way.
Had a student “mix” epoxy for a golf cart frame He forgot the catalyst The epoxy dried eventually and is still on the golf cart frame 6 years later
I once painted some parts using my own witch's brew and it turned out to be a soft mess. Out of desperation, I rigged up some inferred (heat) lamps, left them on overnight, and went home for a sleepless night. The next morning the paint was rock hard so I lucked out on that one. That wasn't epoxy but I have to believe that actual epoxy paint responds even more better to heat.