Is epoxy still good after a winter in an unheated garage or workshop?

Possibly, but test it before you trust it on a project. UltraClear epoxy has a shelf life of about 1 year when stored indoors at room temperature in a closed box, and that is how we recommend storing it. An unheated garage, shed or workshop that drops below freezing is not room-temperature storage.

If your epoxy sat in below-freezing temperatures over the winter: 1. Check its age. If it is more than a year old, we recommend simply ordering fresh material to be safe. 2. If it is within the 1-year shelf life, bring it indoors and let it acclimate fully back to room temperature before doing anything else. 3. Mix and pour a small test batch first to confirm it performs properly before using it on your project. 4. If the test doesn't come out right, order fresh epoxy.

For reference, the shelf life is about 1 year for UltraClear Bar & Table Top Epoxy (room temperature, closed box); about 1 year unopened and about 2 months once opened for UltraClear Deep Pour Epoxy; and about 12 months unopened for UltraClear Art & Craft Epoxy when stored in a cool, dry place.

A brief freeze during shipping is a different matter: that does no harm as long as the epoxy is warmed back to room temperature and fully liquid before use.