Tested some of my old resins before ordering new ones, and I think it’s safe to say that this one should not be used any more. Unless for very specific purposes, like doll-sized milkshakes.
(Not every craftster out there, newbie or not, seems to know that PU-resin usually has a very limited shelf life. It does not like contact with air, especially humid air. Even if it still looks fine in the can/bottle, even if you screwed the lid on reeeeeally tight or even vacuum-sealed it… Sometimes this just happens. Yet there’s also resins that age rather well despite being badly stored, and cure properly even when the individual components start to get flake-y or crystallized. Sometimes a resin can even be one kind in this batch and another in the next. My advice for both old and brand new resin: Always run a little test before pouring it into your mould!)
Smooth Cast PU-Resin Resin Casting Resin BJD Resin Test Propmaking This Is One of the Main Reasons I Don't Use Smooth Cast Anymore Super Short Shelf Life Very Sensitive to Humidity Yellows Pretty Quickly Not Very Strong Either ...I Found It Kinda Rubbish to Be Honest At Least for Dolls It's Fine for Things of a Slightly Lesser Standard Like Props Blog Post Milkshake