Maybe due to the shop temp. The can should be at least room temp 72. or better. When I go out to my shop and turn on the heat, I place my spray cans in front of the heater to warm them up. ( NOT TOO CLOSE, NOT TOO HOT) Just warm them up before you start using them. It might do the trick. I think the colder temps might separate the ingredients. But then again I might be wrong, worth a try.