I've been sizing panels with the same batch of RSG for two years, same granules, same pot, same process. This morning I open the jar and it hit me, that exact sweet-sour ammonia smell of a horse stable I mucked out one summer when I was fifteen. Can't use it now. Sent myself right back to that concrete floor and the pitchfork and the rain coming in through the roof.

I know old glue degrades. But it didn't change texture or tack. Just the smell flipped a switch and now I can't un-smell it. Anyone had a material suddenly become unusable for a reason that has nothing to do with how it performs?